Aarushhh/wikipedia-simple-splitted huggingface dataset:
Herefordshire (known as County of Herefordshire) is a county  in the West Midlands region of England. It borders the English counties of Shropshire to the north, Worcestershire to the east, Gloucestershire to the south east and the Welsh counties of Gwent to the south west and Powys to the west. It is not to be confused with Hertfordshire, a county north of London.

It is pronounced  (i.e. first syllable as in "herring", and -e- a separate syllable).

The county town of Herefordshire is the cathedral city of Hereford.

Waterways
Historically, the Rivers Wye and Lugg were navigable but the wide seasonal variations in water levels mean that few craft larger than canoes and coracles are now used.  There are canoe centres at The Boat House, Glasbury-on-Wye, the Hereford Youth Service  and Kerne Bridge  Ross-on-Wye, as well as a rowing club in Hereford.
The early nineteenth century saw the construction of two canals, The Hereford & Gloucester Canal and The Leominster &  Stourport Canal but these were never successful and there are now few remains to be seen.

Other websites 
The Hereford Times Local news, sport & information
Herefordshire Portal Local events, jobs, photos and news
Herefordshire Libraries 10 Libraries across Herefordshire

References

Unitary authorities

 
Ceremonial counties of England
A conch is a sea-dwelling mollusc. It is a marine gastropod. The ch at the end of 'conch' may be pronounced hard or soft.

Many other gastropods have common names with conch in them. They are however not true conches, in the family 
Strombidae. One such example is the Horse Conch (Pleuroploca gigantea).  The genus Strombus is made up of the true conches. 

While most Strombid species are extinct, at least 65 species still exist. Of these, most are in the Indo-Pacific Oceans while six are in the greater Caribbean region. Living true conch species include the Queen Conch, Strombus gigas, and the West Indian Fighting Conch (Strombus pugilis). 

Many conch, such as the Queen Conch, are found among beds of sea grass in warm tropical waters.

Strombus gigas is included in Appendix II of the UNEP's CITES list of endangered species and international trade is heavily restricted.

Anatomy
Anatomy 

Conches have spirally constructed shells. Depending on species (or aberrant growth patterns), shell growth can be sinistral (left-handed) or dextral (right-handed).

Conches have long eye stalks, a long and narrow aperture, and a siphonal canal with an indentation near the anterior end. This indentation is called a stromboid notch. They also have a foot ending in a pointed, sickle-shaped, horny operculum. They grow a flared lip on their shells upon reaching sexual maturity.  

Conches have a characteristic leaping motion, using their pointed, sickle-shaped, horny operculum to propel themselves forward. They lay eggs in long, gelatinous strands.

Human use 

The animal inside the shell is eaten, either raw, as in salads, or cooked, as in fritters, chowders, gumbos, and burgers. In East Asian cuisines, the meat is often cut into thin slices and then steamed or stir-fried. Conch meat is also often confused with Scungilli, which is more accurately whelk meat.
Conch shells are sometimes used as decoration, as decorative planters, and in cameo-making. As with other mollusk shells, they are ground up into an ingredient in porcelain. In classic Mayan art, conches are shown being utilized in many ways including as paint and ink holders for elite scribes, as bugle or trumpet, and as hand weapons (held by combatants by inserting their hands in the aperture).

In some countries, cleaned Queen Conch (Strombus gigas) shells or polished fragments are sold, mainly to tourists, as souvenirs or in jewelry. Without a permit however, export is a breach of CITES regulations and may lead to arrest  . This is most likely to occur on return to the tourist's home country while clearing customs. In the UK conch shells are the 9th most seized import. 

Conch shells are occasionally used as a building material, either in place of bricks or as bulk for landfill.

It is also believed to be used as a weapon by the earliest Caribbean natives.
Playing the conch shell 
Conch shells are sometimes made into crude bugles by removing the small tip of the shell to form a mouthpiece. Such instruments are used in the Pacific Islands as well as in many parts of Asia.  While lacking the range capabilities and tonal quality of brass instruments, the conch shell is still an interesting instrument to play. As it has no mouthpiece or valves, the embouchure in shell playing is critical. Most shells will only naturally play one note, but with pitch manipulations, multiple sounds can be achieved.  The insertion of the hand and the placement of the fingers will also change the pitch of the shell.  The conch shell is said to be the musical instrument of mermaids and mermen. Steve Turre is the leading innovator of the shell.  It is sometimes found in classical works, such as the symphony piece "La Noche de Los Mayas", or "Night of the Mayas", which was premiered in 1939 with Jacob Watkins on percussion and conch.

Religious symbolism

Hindu tradition
Hindu tradition

The conch shell is a major Hindu article of prayer, used as a trumpeting announcement of all sorts. The God of Preservation, Vishnu, is said to hold a special conch, Panchajanya, that represents life as it has come out of life-giving waters. In the story of Dhruva the divine conch plays a special part. The warriors of ancient India would blow conch shells to announce battle, such as is famously represented in the beginning of the war of Kurukshetra in the Mahabharata, the famous Hindu epic. The conch shell is a deep part of Hindu symbolic and religious tradition. To this very day, many Hindus use the conch as a part of their religious practices, blowing it during worship at specific points, accompanied by ceremonial bells.

See also: Krishna

Buddhist tradition
Buddhism also has incorporated the conch into its symbolism. See: Buddhist symbolism.
Literature 
William Golding's Lord of the Flies features frequent references to "The Conch". In the novel, a conch shell is blown to call the other boys together. It is held by whoever is speaking at meetings, symbolically representing democracy and order. When Roger, Jack's lieutenant, smashes the shell, it is a sign that civilized order has collapsed and Jack's domination has begun.

Media

Bivalves
Gloucestershire (pronounced ; GLOSS-ter-sher) is a county in South West England. The county includes part of the Cotswold Hills, part of the flat fertile valley of the River Severn, and the entire Forest of Dean.

The county town is Gloucester, and other principal towns include Cheltenham, Stroud, Cirencester, and Tewkesbury.

Gloucestershire borders the county of Gwent in Wales, and in England the counties of Herefordshire, Worcestershire, Warwickshire, Oxfordshire, Wiltshire, Somerset and Bristol.

Economy 
This is a chart of trend of regional gross value added of Gloucestershire at current basic prices published (pp.240-253) by Office for National Statistics with figures in millions of British Pounds Sterling.

Antiquities and Other Places of interest 
 Berkeley Castle, an example of a feudal stronghold.
 Beverston Castle
 Calcot Manor
 Forest of Dean
 Hailes Abbey
 Owlpen Manor
 Sudeley Castle
 Tewkesbury Abbey
 Tyndale Monument
 Wildfowl and Wetland Trust, Slimbridge
Other websites 
 Gloucester County Official Site 
 Gloucester City Council website
 Visit Gloucester Site
 Gloucester jobs
 Gloucestershire County Council 
 Gloucestershire Tourism Partnership 
 Official site for Cotswolds tourism
 Yate and Chipping Sodbury Guide  - A Guide to Yate and Chipping Sodbury in South Gloucestershire
 Archaeological Handbook of Gloucestershire by George Witts
 Tales of the River Severn  by Chris Witts

Ceremonial counties of England
Cowry shells (or cowrie), are marine snails of the family Cypraeidae.

They are found chiefly in tropical regions. There are about 200 different species of cowry.

Shell 
The shell itself is almost always very smooth and shiny. They have with a long, narrow, slit-like opening. All varieties have a porcelain-like shine  and many have colorful patterns. In life the shell is covered by the slippery mantle.

Shell sizes range from 5 mm (1/5") for some tropical species to 15 cm (6") for the tiger cowry, Cypraea tigris.

Predators
The slippery shell is very difficult for most animals to grip. The very narrow toothed aperture of the cowry shell makes it difficult for predators to reach into. However cowries are still vulnerable to predation:
Some tropical crustaceans can break the dorsum of a cowry shell.
 Some mollusc-eating cones like Conus textile can inject venom into the cowry's flesh. The cone then extends its stomach into the shell, through the slit, to completely ingest the flesh.
 Some octopuses can gouge a small hole (using a special barb/tooth and an acidic secretion) through the shell to inject a venom that kills the animal within.

Taxonomy
For nearly 200 years, every species in the family Cypraeidae was placed in one genus, Cypraea, but in 2002  the cowries were divided into many different genera.
Uses 
Cowries (esp. Cypraea moneta) were used as a currency in Africa (Ghanaian cedi in Ghana named after cowry shells) and elsewhere, such as in China where the shell or copies of the shell were in theory used as a means of exchange. They are also worn as jewelry or otherwise used as ornaments or charms, as they are viewed as symbols of womanhood, fertility, birth and wealth.  Many find the shiny, porcelain-like shells pleasing to look at.

Cowry shells are sometimes used in a way similar to dice, e.g., in board games like Pachisi, or in divination (cf. Ifá and the annual customs of Dahomey).
A number of shells (6 or 7 in Pachisi) are thrown, with those landing aperture upwards indicating the actual number rolled.

Cowries have also been used in the recent past as a frame over which sock heels were stretched for darning. The cowry ridges allowed the needle to get under the cloth more easily.
The Ojibway aboriginal people in North America used the cowry shells in ceremonies, and the Whiteshell Provincial Park in Manitoba, Canada is named after this type of shell.  There is some debate about how they traded for or found these shells so far inland, away from the natural sources.  Oral stories and birch bark scrolls seem to indicate that they were found in the ground, and/or washed up on the shores of lakes or rivers.  The cowry shells so far inland may indicate the use of them by an earlier tribe or group in the area, and an extensive trade network in the ancient past.

The typewritten postage stamps of 1895 Uganda also are called "Cowries".

References

Other websites 

 cowrys.org 
 Cowrie Genomic Database Project 
 Genus Cypraea on Animal Diversity Web 
 Cowries.info

Gastropods
Former currencies
Currency of Africa
Wiltshire (short: Wilts) is an English county. It borders the counties of Hampshire, Dorset, Somerset, Gloucestershire, Oxfordshire and Berkshire, and contains the unitary authority of Swindon. The county town is Trowbridge, in the west of the county at . The county covers 858,931 acres (3476 km²)

Settlements
Notable towns and cities in Wiltshire are:
 Bradford on Avon
 Calne
 Chippenham
 Devizes
 Malmesbury
 Marlborough
 Salisbury (city)
 Swindon
 Trowbridge
 Warminster
 Westbury

A full list of settlements is at List of places in Wiltshire.

Places of interest

Notable places of interest in Wiltshire are:

Notable areas of countryside in Wiltshire are:
 Cranborne Chase 
 Marlborough Downs 
 Salisbury Plain 
 Vale of Pewsey
Notable routes through Wiltshire are:
 A4 road
 M4 motorway
 A303 trunk road
 Fosse Way old Roman road
 Great Western Main Line railway
 Wessex Main Line railway
 Kennet and Avon Canal
 Swindon and Cricklade Railway 
 Thames Path, a long-distance footpath
 Wiltshire Cycleway
 National Cycle Route 4

Wiltshire is "Mid-Wessex" in the novels of Thomas Hardy

Other websites 

 Wiltshire County Council
 List of Councillors 
 Wiltshire Constabulary Online 
 BBC Wiltshire
 Wiltshire Tourist Office
 John Aubrey's The Natural History of Wiltshire
 White horses of Wiltshire 
 Wiltshire Gazette & Herald
 Wiltshire Times & Chippenham News
 Geology map of Wiltshire (PDF)
 Wiltshire & Swindon Intelligence Network

 
Ceremonial counties of England
The County of West Midlands is a metropolitan county in western central England with a population of around 2,600,000 people. The county contains three major cities, these being Birmingham, Coventry and Wolverhampton. Other large settlements in the county include Sutton Coldfield, Solihull, and the Black Country towns of Dudley, Walsall and West Bromwich.

The name "West Midlands" is also used for the much larger West Midlands region, which sometimes causes confusion.

Geography 
The West Midlands borders the counties of Warwickshire to the east, Worcestershire to the south, and Staffordshire to the north.

The West Midlands is one of the most heavily urbanised counties in the UK. Birmingham, Wolverhampton, the Black Country and Solihull together form the largest conurbation in the UK outside London, with a combined population of around 2.27 million.
The West Midlands is not entirely urban; Coventry is separated from the Birmingham urban area, by stretch of green belt land roughly 15 miles across known as the "Meriden Gap", which retains a strongly rural character.

A smaller piece of green belt between Birmingham, Walsall and West Bromwich includes Barr Beacon and the Sandwell Valley.

Towns and villages 
 Aldridge
 Balsall Common, Bloxwich, Bilston, Birmingham. Blackheath, Brierley Hill
 Coventry
 Dorridge, Dudley
 Halesowen, Hampton-in-Arden
 Little Aston
 Marston Green, Meriden
 Oldbury
 Rowley Regis
 Sedgley, Smethwick, Solihull, Stourbridge, Sutton Coldfield, Streetly
 Tipton
 Walsall, Wednesfield, Wednesbury, West Bromwich, Wolverhampton
Places of interest 
 Aston Hall, Birmingham
 Bescot Stadium (Walsall FC)
 Birmingham Bullring
 Birmingham Museum & Art Gallery
 Birmingham Hippodrome
 Birmingham Railway Museum
 Birmingham Wheel
 Black Country Living Museum
 Blakesley Hall
 Cadbury World, Bournville, Birmingham
 Coventry Cathedral
 Coventry SkyDome Arena
 Coventry Transport Museum
 Dudley Castle
 Dudley Zoo
 Edgbaston Cricket Ground, Birmingham
 Internation Convention Centre (including Symphony Hall), Birmingham
 Molineux stadium (Wolverhampton Wanderers F.C.)
 National Exhibition Centre
 National Indoor Arena (NIA), Birmingham
 Netherton tunnel
 Perrott's Folly
 Ricoh Arena (Coventry City Football Club)
 Sarehole Mill
 Sea Life Centre, Birmingham
 St Andrews (Birmingham City Football Club)
 The Hawthorns, (West Bromwich Albion Football Club)
 Thinktank, Millennium Point, Birmingham
 Villa Park (Aston Villa Football Club)
 Walsall Art Gallery
 Wightwick Manor
Education 
The West Midlands contains 6 universities;
 University of Birmingham
 Aston University
 University of Central England
 University of Warwick
 Coventry University
 Wolverhampton University

Though Warwick and Birmingham are considered the most prestigious of the universities in the area, all have a large intake of students from around the country.

Other websites 
 Photographs of Birmingham and the West Midlands
 Identity in the West Midlands 
 West Midlands Joint Committee 
 West Midlands NO! Campaign 
 West Midlands Groups Communities 

 
Ceremonial counties of England
A conurbation is an urban area that includes a number of cities, towns and villages which, through population growth and expansion, have physically merged to form one continuous built up area. It is a sort of agglomeration.

A metropolitan area usually combines one or several conurbations.

Settlements
Urban geography
Dunkirk (, pronounced  or ; ) is a harbour city in the northernmost part of France, 10 km (6 mi) from the Belgian border.
 
The population of the whole metropolitan area was of 265,974 at the 1999 census. 

Until the middle of the 20th century the city was in the Dutch language area; today the local Dutch dialect still can be heard but has largely given way to French.

History 
Dunkirk was first mentioned in 1067 as Dunkerk (). 

In World War II, heavy fighting took place around Dunkirk during the German invasion in 1940 (Battle of Dunkirk), but a lull in the action unexpectedly allowed a large number of French and British soldiers to escape to England. The British evacuation of Dunkirk through the English Channel was codenamed Operation Dynamo. 
During the war, Dunkirk was largely destroyed by bombing.

Postwar Dunkirk 

On 14 December 2002, the Norwegian auto carrier Tricolor collided with the Bahamian-registered Kariba and sank off Dunkirk harbour, causing a hazard to navigation in the English Channel.
Communes 
Since 9 December 2010, the former communes of Fort-Mardyck and Saint-Pol-sur-Mer were merged into the commune of Dunkirk.

Economy 
Dunkirk has the third largest harbour in France, after those of Le Havre and Marseille. It is also an industrial city, heavily dependent on the steel, food processing, oil refining, ship building and chemical industries.

Tourist attractions 

 The Musée Portuaire hosts exhibits images about the history and presence of the port.
 The Musée des Beaux-Arts has a large collection of Flemish, Italian and French paintings and sculptures.
 The Carnival of Dunkirk

Miscellaneous

Transport 

Dunkirk has a ferry connection with Dover in England.

Twin towns 

Dunkirk is twinned with:
  Krefeld, Germany since June 15, 1974
  Middlesbrough, United Kingdom since April 12, 1976

Dunkirk has cooperation agreements with:
 Dartford district, United Kingdom since March 1988
 Thanet district, United Kingdom since June 18, 1993

References

Other websites
Other websites 

 City council website 
 Tourist office website

 
Port cities and towns of the North Sea
Limburg-Weilburg is a Landkreis (rural district) in the west of Hesse, Germany.

History 
1867 the Oberlahnkreis with the capital Weilburg was created. In 1886 Limburg an der Lahn district was set up, with the capital Limburg. In 1974 both districts were joined together.

Geography 
The district is located between the two mountain areas Westerwald and Taunus. The main river is the Lahn.

Coat of arms

Towns and municipalities

References

Other websites

 Official website  (German)
Elz is a municipality and a village in Hessen, Germany. It is part of the Landkreis Limburg-Weilburg. It is along the river Lahn. It has 8,088 inhabitants (2004).

Geography 
The elevation is between 110m and 291m above sea level. Elz is in a valley called "Limburger Becken", which surrounds the town of Limburg. Elz is also in the valley of the "Elbbach", which flows into the river Lahn after passing Elz.
The municipality of Elz borders the municipalities of Hundsangen, Hambach, Görgeshausen, Niedererbach, Obererbach and the towns of Hadamar and Limburg.
The municipality of Elz consists of two villages: The village of Elz (7,743 inhabitants) and the village of Malmeneich (345 inhabitants).
Average temperatures are 10.5 °C in Elz and 9.9 °C in Malmeneich. Though this sounds quite moderate, temperatures can vary between -20 °C in winter and 40 °C in summer. In an average year there are 600mm of rain in Elz and 720mm in Malmeneich.
History 
Elz was first mentioned in a document from 933 AD, which does not exist any more. Political importance resulted from its position at the Hohe Straße, the former most important road between Frankfurt am Main and Cologne, which still exists and is now part of the "Bundesstraße 8", which can be translated with Interstate 8.
Elz got the town privileges in 1442. Soon a wall around the town was constructed but knocked down later.

Politics 
The council consists of 31 members. 19 members are from the Christian Democrats, seven are from the Social Democratic Party, four from the Free Voters' Community and one is from the Green Party. The mayor Horst Kaiser is a Christian Democrat and was elected in 2005 with 84.8% of all votes.

Economy and infrastructure 
In Elz thaere are more than 600 businesses with much more than 2,000 jobs. The industrial area is at the B8 between Elz and Malmeneich.
Traffic 
Elz is not only at the B8,which goes from the Dutch border to Passau, but also at the Autobahn 3, which connects Würzburg,Frankfurt am Main and Cologne.

Public institutions 
In Elz there is a big outdoor swimming pool, two gyms, several sport and tennis fields and two old people's homes.

Education 
There are three kindergartens, two primary schools and one "Haupt- und Realschule" (part of the German secondary education).

Famous people 
 Theodor Blank (1905-1972), Bundesverteidigungsminister (Federal minister for defense) 1955-1956, Bundesminister für Arbeit und Sozialordnung (Federal minister for employment and social matters) 1957-1965
 Joseph Blank (1913-1994), Landesminister für Landesplanung, Wohnungsbau und öffentliche Arbeiten von Nordrhein-Westfalen (Minister for spatial planning, building and public works of North Rhine-Westphalia) 1962-1963

References
The Cephalopoda (Greek meaning "head-foot") is an important mollusc class. They have bilateral symmetry, a head, and arms or tentacles. Teuthology, a branch of malacology, is the study of cephalopods.

The class has two living subclasses. In the Coleoidea, the mollusc shell has become smaller, or is not there at all; this subclass has the octopus, squid, and cuttlefish. The Nautiloidea have a shell; Nautilus is its only living genus.

There are at least 800 different living species of Cephalopods. Two important extinct taxa are the ammonites, and the belemnites (order Belemnoidea, of class Coleoidea). Cephalopods are found in all the oceans of the world and at all pelagic levels. None of them can live in freshwater (water with no salt in it), but a few species live in brackish (partly salty) water.

Cephalopod groups 
Nautiloids: Nautilus 
Ammonoids: Ammonites (extinct)
Coleoids
Belemnites (extinct)
Squid (4 different groups)
Cuttlefish (Sepia)
Octopus
Number of species
There are still discoveries of new species of cephalopods:
1998: 703 recent species 
2001: 786 recent species  
2004: estimate: from 1000 to 1200 species 

There are many more fossil species. It is thought there are around 11,000 extinct taxa.

Nervous system and behaviour 
Cephalopods are the most intelligent invertebrates and have good senses and large brains. The nervous system of cephalopods is the most complex of the invertebrates, and their brain to body mass ratio falls between that of warm and cold blooded vertebrates. The giant nerve fibers of the cephalopod mantle have been a favourite experimental material for many years; their large diameter makes them easier to study.

Colour and light
Colour and light 

Most cephalopods have chromatophores – that is, cells with different colours – which they can use in a number of surprising ways. As well as blending with their background, some cephalopods bioluminesce, shining light downwards to hide their shadows from any attackers. The bioluminescence is made by bacterial symbionts; the host cephalopod is able to find the light made by these animals. Bioluminescence may also be used to attract prey, and some species use colourful shows to get mates, amaze predators, or even signal to one another.

Colouration 
Colouration can be changed in milliseconds as they adjust to their environment, and the pigment cells can expand or contract. Rapid colour change is usually more common in near-shore species than those living in the open ocean. Those in open ocean mostly use camouflage to make their body outline less easy to see.
Evidence of original colouration has been found in cephalopod fossils as far back as the Silurian; certain straight-shelled species had lines round their shell, which are thought to have used as camouflage of their body outline. Devonian cephalopods bear more complex colour patterns, whose function may be more complex.

Moving around 
Cephalopods usually move by jet propulsion (squirting water). This uses a lot of energy to travel compared to the tail propulsion used by fish. They use jet propulsion because they do not have fins or flippers. The efficiency of jet propulsion goes down with larger animals. This is probably the reason why many species use their fins or arms for moving if possible.
Oxygenated water is taken into the mantle cavity to the gills. By contracting the mantle's muscles, the water is pushed out through the siphon, made by a fold in the mantle. Motion of the cephalopods is usually backward as water is forced out forwards, but the siphon can be pointed in different directions. Some cephalopods can adjust their body shape to move through the water more easily.

Some octopus species are also able to walk along the sea bed. Squids and cuttlefish can move short distances in any direction by moving a flap of muscle around the mantle.

Ink 
With the exception of the Nautilidae and the species of octopus of the suborder Cirrina, all known cephalopods have an ink sac, which can be used to push out a cloud of dark ink to confuse predators.

Blood 
Like most molluscs, cephalopods use haemocyanin, a copper-containing protein, rather than haemoglobin to transport oxygen.  As a result, their blood is colourless when deoxygenated and turns blue when placed in air.
Reproduction and life cycle 
With a few exceptions, Coleoideans live short lives with fast growth. Most of the energy from their food is used for growing. The penis in most male Coleoidea is a long and muscular end of the vas deferens (tube for sperms) used to transfer spermatophores (sperm packages) to a modified arm called a hectocotylus. That in turn is used to transport the spermatophores to the female. In species where the hectocotylus is missing, the penis is long and able to extend beyond the mantle cavity and transfers the spermatophores directly to the female. The females lay many small eggs in one batch, and die afterwards. The Nautiloidea, on the other hand make a few large eggs in each batch, and live for a long time.
Evolution 
The class developed during the late Cambrian and were the most common and varied marine life forms during the Palaeozoic and Mesozoic eras. Tommotia, an early cephalopod, had squid-like tentacles but also a snail-like foot it used to move across the sea floor. Early cephalopods were at the top of the food chain.

The old (cohort Belemnoidea) and modern (cohort Neocoleoidea) coleoids, as well as the ammonoids, all diverged (evolved away) from the external shelled nautiloids during the middle Paleozoic Era, between 450 and 300 million years ago. Most ancient varieties had protective shells. These shells at first were conical but later developed into the curved shapes seen in modern nautilus species. Shells inside the body still exist in many living cephalopod groups, such as cuttlefish. The most famous group with external shells, the ammonites, became extinct at the end of the Cretaceous period.

References
References

Other sources
Berthold, Thomas, & Engeser, Theo. 1987. Phylogenetic analysis and systematization of the Cephalopoda (Mollusca). Verhandlungen Naturwissenschaftlichen Vereins in Hamburg. (NF) 29: 187-220.
Engeser, Theo. 1997. Fossil Nautiloidea page. <http://userpage.fu-berlin.de/~palaeont/fossilnautiloidea/fossnautcontent.htm>
Felley J. Vecchione M. Roper C.F.E. Sweeney M. & Christensen T. 2001-2003: Current classification of Recent Cephalopoda. internet: National Museum of Natural History: Department of Systematic Biology: Invertebrate Zoology: http://www.mnh.si.edu/cephs/ 
Shevyrev A.A. 2005. The Cephalopod macrosystem: a historical review, the present state of knowledge, and unsolved problems: 1. Major features and overall classification of cephalopod molluscs. Paleontological Journal. 39: 606-614. Translated from Paleontologicheskii Zhurnal #6, 2005, 33-42.

Other websites
Other websites 

CephBase - cephalopod database 
TONMO.COM - The Octopus News Magazine Online - cephalopod articles and discussion
Tree of Life Web Project - Cephalopoda 
Mikko's Phylogeny Tree 
Articles on various fossil cephalopod topics for non-specialists 
Fish vs. Cephalopods
Will Fast Growing Squid Replace Slow Growing Fish?
Bipedal Octopuses with links to video and original paper 
 Palcephalopoda/Neocephalopoda Hypothesis
Biomineralisation in modern and fossil cephalopods 
 Cephalopods
Cuttlefish are marine Cephalopod molluscs. They belong to the same class as squid, octopodes and the nautilus.

Cuttlefish have an internal shell (called a cuttlebone), large eyes, and eight arms and two tentacles furnished with finely toothed suckers, with which they grab their prey.

Cuttlefish eat small molluscs, crabs, shrimp, fish and other cuttlefish. Various sharks and fish prey on them. They live about 1 to 2 years.

Anatomy
Anatomy

Cuttlebone 
Cuttlefish have an internal cuttlebone, made of calcium carbonate. It is porous, full of small holes, The buoyancy of the cuttlebone can change, allowing the cuttlefish to go lower or higher by changing the amount of gas and liquid in its chambers. The cuttlebone of each species has a distinct shape, size, and pattern of ridges or texture. Cuttlebones are used by jewellers and silversmiths as moulds for casting small objects. They are probably better known today as the material given to pet birds as a source of calcium. The cuttlebone is only found in cuttlefish, and is one of the features that makes them different from squid and other molluscs.
Changing color 
Cuttlefish are sometimes called the chameleon of the sea because they are able to change their skin color. Their skin can flash a colorful pattern in order to communicate with other cuttlefish and to camouflage them from predators. This color-changing function is produced by groups of red, yellow, brown, and black pigmented chromatophores above a layer of reflective iridophores and leucophores. These are all in the cuttlefish's skin, and work together to change its colour. There are up to 200 of these special pigment cells per square millimeter.

The pigmented chromatophores have a sac of pigment and a large membrane that is folded when retracted. There are 6-20 small muscle cells on the sides which can contract to squash the elastic sac into a disc against the skin.
Eyes 
Cuttlefish eyes are among the most developed in the animal kingdom. The way cephalopod eyes develop is fundamentally different from that of vertebrates like humans, but the way they work is rather similar. The similarity between cephalopod and vertebrate eyes is an examples of convergent evolution. Although they cannot see color, they can perceive the polarization of light, which improves their ability to see contrast. They have two spots of concentrated sensor cells on their retina (known as fovea), one to look more forward, and one to look more backwards. The lenses, instead of being reshaped as they are in humans, are instead pulled around by reshaping the entire eye in order to change focus.
Blood 
The blood of a cuttlefish is an unusual shade of green-blue because it uses the copper-containing protein haemocyanin to carry oxygen instead of the red iron-containing protein haemoglobin that is found in vertebrates. This is similar to the blood of arthropods. Haemocyanin is not as good at carrying oxygen as haemoglobin. The blood is pumped by three separate 'hearts'. Two of these are used for pumping blood to the cuttlefish's pair of gills (one heart for each gill), and the third for pumping blood around the rest of the body.

Human interest

Ink 
Cuttlefish have inks like squid and octopuses. As with squid, the ink is a defensive tool, squirted out to cover its retreat in the case of danger. This ink was formerly an important dye, called sepia. Today artificial (not natural) dyes have replaced natural sepia.
Cuttlefish as food 
Cuttlefish are caught for food in Mediterranean, and East Asian cultures. Although squid is more popular as a restaurant dish all over the world, in East Asia dried cuttlefish is highly popular.

Cuttlefish is popular in Italy and Croatia, where it is used in Risotto Nero. "Nero" means 'black', which is the colour the rice turns because of the cuttlefish ink. Spanish cuisine often uses cuttlefish and squid ink for cooking due to the marine flavor and smoothness that it provides to the meals and it is included in dishes such as rice, pasta and fish stews.

Cuttlefish in literature 
Cuttlefish made their most important literary appearance in the title of Eugenio Montale's collection of poetry called Cuttlefish Bones (Ossi di seppia), published in Turin in 1925. Montale was awarded the Nobel Prize for Literature in 1975.

Classification 

There are over 120 species of living cuttlefish, in 5 genera. Sepiadariidae contains seven species and two genera; all the rest are in the Sepiidae.
CLASS CEPHALOPODA
Subclass Nautiloidea: nautilus
Subclass Coleoidea: squid, octopus, cuttlefish
Superorder Octopodiformes
Superorder Decapodiformes
Order Spirulida: Ram's Horn Squid
Order Sepiolida: bobtail squid
Order Teuthida: giant squid
Order Sepiida: cuttlefish
Suborder Sepiina
Family Sepiadariidae
Family Sepiidae

References

Other websites 
Scientific Database with photos and videos of cuttlefish and other cephalopods 
TONMO.com offers articles and forum discussion on cuttlefish care
YouTube video of a cuttlefish harassing a diver
YouTube video of cuttlefish hovering about. You can see colour changes and movement.
Amazing cuttlefish – Cephalopods with natural camouflage and sepia ink 
Diving with cuttlefish

Cephalopods
Nautilus is the common name for cephalopods of the family Nautilidae. They are the only living members of the subclass Nautiloidea. In appearance, they have not changed much in millions of years. The term chambered nautilus is also used for any species of the Nautilidae.

Many biologists see them as 'living fossils', because they are the only living descendents of the group which gave rise to the ammonites in the Palaeozoic era.

Today, there are six living species in two genera. The species Nautilus pompilius, from Western Australia is the largest and best known. It get up to 27 cm in diameter. However, most other nautiluses never exceed 20 cm. The Bellybutton nautilus, Nautilus macromphalus, is the smallest species, usually measuring only 16 cm.

The radula is wide and has exactly nine teeth. There are two pairs of gills.

The shell
The shell

Nautiluses are the only cephalopods who have an external shell. This is an ancestral or basal, feature. The animal can withdraw completely into its shell. It can the close the opening with a leathery hood formed from two specially folded tentacles. The shell is coiled and calcareous, with mother-of-pearl lining. It is pressure resistant, but will implode at a depth of about 800 m. The nautilus shell is made of two layers: the outer layer is a dull white, while the inner layer is a striking white with iridescence. The innermost portion of the shell is pearlescent, blue-gray. A osmena pearl is not a pearl, but a jewellery product got from this part of the shell.
The shell is internally divided into chambers. All the walls between chambers ('septa') are pierced in the middle by a duct, the siphuncle. Through this the animal can change the air pressure in the chambers. As the nautilus matures its body moves forward, sealing each chamber in turn with a new septum (wall). The last fully open chamber, the largest one, is used as the living chamber. The number of chambers increases from around four at the moment of hatching to thirty or more in adults.

The shell colour keeps the animal hidden in the water. When seen from the top, the shell is darker in color and marked with irregular stripes, which makes it blend into the darkness of the water below. The underside is almost completely white, making the animal indistinguishable from brighter waters near the ocean surface. This mode of camouflage is called countershading.

The nautilus shell is one of the finest natural examples of a logarithmic spiral.

Natural history
Natural history

Buoyancy and movement
In order to swim, the nautilus draws water into and out of the living chamber and makes use of jet propulsion. When water is inside the chamber, the siphuncle extracts salt from it and diffuses it into the blood. When water is pumped out, the animal adjusts its buoyancy with the gas contained in the chamber. Buoyancy can be controlled by the  pumping of gas and fluid into or from the chambers using the siphuncle. The control of buoyancy like this limits the nautilus; they cannot operate under extreme pressure.

In the wild, nautilus usually lives in depths of about 300 m, rising to around 100 m at night for feeding, mating and egg laying. The shell of the nautilus cannot withstand depths greater than approximately 800 m.
Diet and sensory system 
Nautiluses are predators and feed mainly on shrimp, small fish and crustaceans, which are captured by the tentacles. However, due to the very little energy they devote to swimming, they need only eat once a month. Unlike other cephalopods, they do not have good vision; their eye structure is highly developed but lacks a solid lens. They have a simple "pinhole" lens through which water can pass. Instead of vision, the animal is thought to use olfaction as the primary sensory means during foraging, locating or identifying potential mates.
Evolution 
Fossil records indicate that nautiloids have not changed much (at least in their body form) for the last 500 million years. Nautiloids were much more common and varied 200 million years ago. Many of the early ones were straight-shelled, as in the extinct genus Lituites. They developed in the Cambrian and became a significant sea predator in the Ordovician period. Some species reached over 2.5 meters in size. The other cephalopod subclass, Coleoidea, diverged from the Nautilidae long ago and the nautilus has remained relatively unchanged since. Extinct relatives of the nautilus include ammonites, which were very important for many millions of years.  Other groups were the baculites and goniatites.
Reproduction and lifespan 
Nautiluses are sexually dimorphic and reproduce by laying eggs. Attached to rocks in shallow waters, the eggs take twelve months to develop before hatching out at around 30 mm long. Females spawn once per year and regenerate their gonads, making nautiluses the only cephalopods to repeat reproduction. The lifespan of nautiluses is about 20 years, which is exceptionally long for a cephalopod.

Distribution 
Nautiluses are only found in the tropical Indian and Pacific Oceans, from 30° N to 30° S latitude and 90° to 185° W longitude. They live on the deep slopes of coral reefs.

Related pages 
Ammonite

References 

Ward, P.D. 1988. In search of Nautilus. Simon and Schuster.

Other websites 

Nautilus pompilius at ARKive 
 Nautilidae discussion forum at TONMO.com 
 Waikïkï Aquarium: Marine Life Profile: Chambered Nautilus 
A molecular and karyological approach to the taxonomy of Nautilus 

Cephalopods
Living fossils
A logarithmic spiral, equiangular spiral or growth spiral is a special kind of spiral curve which often appears in nature. The logarithmic spiral was first described by Descartes and later extensively investigated by Jakob Bernoulli, who called it Spira mirabilis, "the marvelous spiral".

Definition
In polar coordinates (r, θ) the curve can be written as

or

hence the name "logarithmic". In parametric form, the curve is

with real numbers a and b.

The spiral has the property that the angle ɸ between the tangent and radial line at the point (r,θ) is constant.  This property can be expressed in differential geometric terms as

The derivative r'(θ) is proportional to the parameter b.  In other words, it controls how "tightly" and in which direction the spiral spirals.  In the extreme case that b = 0 (ɸ = π/2) the spiral becomes a circle of radius a.  Conversely, in the limit that b approaches infinity (ɸ → 0) the spiral tends toward a straight line.  The complement of ɸ is called the pitch.
Spira mirabilis and Jakob Bernoulli
Spira mirabilis, Latin for "miraculous spiral", is another name for the logarithmic spiral. While this curve had already been named by other mathematicians, the name "miraculous" or "marvelous" spiral was given to this curve by Jakob Bernoulli, because he was fascinated by one of its unique mathematical properties: the size of the spiral increases, but the shape stays the same with each added curve. Maybe because of this property, the spira mirabilis has evolved in nature, seen in some living beings, such as nautilus shells and sunflower heads.  Jakob Bernoulli wanted the shape on his headstone, but, by error, an Archimedean spiral was placed there instead.

Notes
The logarithmic spiral can be distinguished from the Archimedean spiral by the fact that the distances between the turnings of a logarithmic spiral increase in geometric progression, while in an Archimedean spiral these distances are constant.
Logarithmic spirals are self-similar in that they are self-congruent under all similarity transformations (scaling them gives the same result as rotating them). Scaling by a factor  gives the same as the original, without rotation. They are also congruent to their own involutes, evolutes, and the pedal curves based on their centers.

Starting at a point P and moving inwards along the spiral, one has to circle the origin infinitely often before reaching it; yet, the total distance covered on this path is finite. This was first realized by Evangelista Torricelli even before calculus had been invented. The total distance covered is r/cos(α), where r is the straight-line distance from P to the origin.
One can construct approximate logarithmic spirals with pitch about 17.03239 degrees using Fibonacci numbers or the golden ratio as is explained in those articles. Similarly, the exponential function exactly maps all lines not parallel with the real or imaginary axis in the complex plane, to all logarithmic spirals in the complex plane with centre at 0. (Up to adding integer multiples of 2πi to the lines, the mapping of all lines to all logarithmic spirals is onto.) The pitch angle of the logarithmic spiral is the angle between the line and the imaginary axis.

Logarithmic spirals in nature
In several natural phenomena one may find curves that are close to being logarithmic spirals. Here follows some examples and reasons:

The approach of a hawk to its prey. Their sharpest view is at an angle to their direction of flight; this angle is the same as the spiral's pitch.
The approach of an insect to a light source. They are used to having the light source at a constant angle to their flight path. Usually the sun is the only light source and flying that way will result in a practically straight line.

The arms of spiral galaxies. Our own galaxy, the Milky Way, is believed to have four major spiral arms, each of which is roughly a logarithmic spiral with pitch of about 12 degrees, an unusually small pitch angle for a galaxy such as the Milky Way. In general, arms in spiral galaxies have pitch angles ranging from about 10 to 40 degrees.

The arms of tropical cyclones, such as hurricanes.
Many biological structures including spider webs and the shells of mollusks. In these cases, the reason is the following: Start with any irregularly shaped two-dimensional figure F0. Expand F0 by a certain factor to get F1, and place F1 next to F0, so that two sides touch. Now expand F1 by the same factor to get F2, and place it next to F1 as before. Repeating this will produce an approximate logarithmic spiral whose pitch is determined by the expansion factor and the angle with which the figures were placed next to each other. This is shown for polygonal figures in the accompanying graphic.

Related pages
Fibonacci sequence
Spring Loaded Camming Device

References
 
 Jim Wilson, Equiangular Spiral (or Logarithmic Spiral) and Its Related Curves , University of Georgia (1999)
 Alexander Bogomolny, Spira Mirabilis - Wonderful Spiral, at cut-the-knot

Other websites 
 Spira mirabilis  history and math

Logarithms
The small white (Pieris rapae) is a small to mid-sized butterfly of the 'yellows' & 'whites' Pieridae family. It is also commonly known as the small cabbage white or just the cabbage white.

Distribution
It is common across Europe, North Africa and Asia and has also been accidentally introduced to North America, Australia and New Zealand where they have become pests on cultivated cabbages and other mustard family crops.

Description

It looks like a smaller version of the Large White. The upperside is creamy white with black tips to the forewings. Females also have two black spots in the center of the forewings. Its underwings are yellowish with black .

Habits
Like its close relative the large white this is a strong flyer and the British population is increased by continental immigrants in most years. Like other 'white' butterflies it hibernates as a pupa. Like the large white, it is sometimes known as the cabbage white' or cabbage butterfly.

Lifecycle
It has two flight periods, April–May and July–August.
Eggs
Its caterpillars can be a pest on cultivated cabbages. . It also lays eggs on wild members of the cabbage family such as the charlock Sinapis arvensis and hedge mustard Sisybrium officinale. The eggs are laid singly on foodplant leaves.

Caterpillars
Known in the United States as "imported cabbage worms", the caterpillars are green and well camouflaged. Unlike the large white they do not store the mustard oils from their foodplants and so are not distastful to predators like birds.

References
 Asher J. et al. The millennium atlas of Britain and Ireland Oxford University Press
 Evans W.H. 1932. The identification of Indian butterflies. 2nd ed, Bombay Natural History Society, Mumbai, India.

Pieridae
Argonauta, the argonauts, is the only living genus in the Argonautidae family. They are a group of pelagic octopods.

They are also called paper nautiluses, because of the paper-thin eggcase that females make. This structure does not have the gas-filled chambers of nautilus shells, and is not a true cephalopod shell. It is an evolutionary innovation unique to the genus Argonauta.

Argonauts are found in tropical and subtropical waters worldwide: they live in open ocean. Like most octopods, they have a rounded body, eight arms and no fins. However, unlike octopuses, argonauts live close to the sea surface rather than on the seabed. Argonauta species have very large eyes and small distal webs. They have a mantle-funnel locking apparatus, which is a way to identify the genus. It consists of knob-like cartilages in the mantle and corresponding depressions in the funnel. Unlike the closely related genera Ocythoe and Tremoctopus, Argonauta species lack water pores.

Physical description
Sexual dimorphism and reproduction
In Argonauts, males and females are quite different in size and lifespan. Females grow up to 10 cm and make shells up to 30 cm, while males rarely grow larger than 2 cm. The males only mate once in their short lifetime, but the females can get pregnant repeatedly. The females have been known since ancient times while the males were only described in the late 19th Century. The males use a modified arm, the hectocotylus, to transfer sperm to the female. For fertilization, the arm is inserted into the female's pallial cavity, then is detached from the male.

The hectocotylus was originally described as a parasitic worm. The hectocotyl arm and its correct function were described by Aristotle. His account was disbelieved for over 2000 years, but was rediscovered in the early 19th century.
Eggcase 
Female argonauts make a laterally compressed, calcareous eggcase in which they live. The eggcase curiously resembles the shells of extinct ammonites. It is secreted by the tips of the female's two greatly expanded dorsal tentacles (third left arms) before egg laying. After she deposits her eggs in the floating eggcase, the female herself takes shelter in it, often along with the male's detached hectocotylus. She is usually found with her head and tentacles protruding from the opening, but she retreats deeper inside if disturbed.

These ornate, curved white eggcases are occasionally found floating on the sea surface, sometimes with the female argonaut still clinging to it. It is made of calcite, with a 3-layered structure The argonauts may have evolved to use ammonite shells for their egg laying, eventually becoming able to mend the shells and perhaps even make their own.