bluuebunny/crossref_metadata_2025_split huggingface dataset:
A revision of the British leeches of the family Erpobdellidae, with a description of Dina lineata (O. F. Müller, 1774), a leech new to British fauna
Authors: Mann K. H. 
Published: August 2010

Summary.

Revised descriptions of the British leeches of the family Erpobdellidae are given, together with accounts of their principal variations.
Since the British Erpobdellidae cannot with certainty be identified by examination of external characters, a technique is described for separating the genera and species by the shape of the genital atrium.
The leech Dina lineata (O. F. Müller, 1774) is recorded in Britain for the first time. It was collected in a roadside pond rich in calcium and in organic matter. It is an isolated occurrence, probably an example of recent colonization.
Erpobdella testacea cannot establish itself in an environment favourable to E. octoculata, but in conditions of sewage pollution, or low total alkalinity, E. testacea becomes dominant.
The division of E. octoculata into var. vulgaris and var. atomaria is of no taxonomic significance, and should be discontinued.
Trocheta subviridis has been found most frequently in London and the Home Counties, but also occurs in Manchester, Gloucester, Glamorgan and Oxford. It is frequently associated with sewage works.
Molarization of the premolars in the Perissodactyla.
Authors: BUTLER P. M. 
Published: August 2010

SUMMARY.

Molarization of the premolars in perissodactyls is reviewed in the light of that of the milk‐molars. The premolar patterns are closely related to those of the milk‐molars, the closest resemblance being shown, in most forms, to the milk‐molar that the premolar replaces. In a few Eocene forms, however, the premolars seem rather to resemble milk‐molars placed further forward in the series.
In primitive perissodactyls, each premolar differs from the corresponding milk‐molar in a number of ways, the most striking of which are the weak development of the talonid on the lower tooth and of the middle part of the crown on the upper tooth. The paracone and metacone of the upper premolar are more closely united than in the corresponding milk‐molar, and the protocone and hypocone are represented by a single cusp, the deuterocone. This condition is termed hyposphyric.
In the course of evolution the hyposphyric condition gives place to an isosphyric condition in which each premolar closely resembles in pattern the corresponding milk‐molar. If the milk‐molar is not yet molariform, further molarization of the milk‐molar and premolar take place together.
The lingual cusp (deuterocone) must be considered as homologous with the protocone and hypocone taken together. When on the milk‐molar the hypocone is larger than the protocone, the deuterocone of the premolar corresponds mainly to the hypocone and is converted into the hypocone as isosphyry increases, the protocone developing from its anterior crest. When the protocone and hypocone of the milk‐molar are equal. the deuterocone divides equally.
On P4 the development of the hypocone is retarded, and the deuterocone corresponds mainly to the protocone. The hypocone when it first develops on P4 is smaller, lower and less lingual than the protocone. In most rhinocerotoids and some tapiroids a lesser degree of retardation of the hypocone occurs on P3.
Molarization of the premolars is thus a complex of a number of processes which can be detected in all perissodactyls. Differences in the method of molarization from group to group are due to the lack of correlation between the processes involved. Differences in the course of evolution followed by adjacent premolars, as in Eocene Equidae and Oligocene Rhinocerotoidea. are to be explained in the same way.
Premolar occlusion is closely related to that of the milk‐molars, corresponding cusps having similar occlusal relations in the two series.
Trematodes of the genus Renicola from birds in British zoos, with descriptions of two new species
Authors: Wright C. A. 
Published: August 2010

Summary.A number of cases of infection of the kidneys in birds by trematodes of the genus Renicola Cohn, 1904 is reported and two new species of the genus are described. One of them, Renicola pelecani sp. n., has been found in both the White Pelican (Pelecanus onocrotalus) and the Spot‐billed Pelican (Pelecanus phillipensis). The other, Renicola sloanei sp. n., has been found in a number of species of penguin. It has also been found in a Common Guillemot (Uria aalge) from Sussex, this being the first record of a Renicola from a wild bird in Great Britain.
The anatomy of the Horse Leech, Haemopis sanguisuya (L.) with particular reference to the excretory system
Authors: Mann K. H. 
Published: August 2010

Summary.The anatomy of the leech Haemopis sangaisaga is described. Whereas all other descriptions of British leeches are based on Whitman's conception of the relation between annulation and segmentation the system here employed is that of Castle and Moore, in which the distribution of the peripheral nerves is used to define the limits of the segments.The alimentary canal differs markedly from that of Hirudo, since the crop has only one pair of lateral diverticula. This may be correlated with the feeding habits, which are macrophagous and not sanguivorous.The nephridia are described in particular detail. It is found that, as in Hirudo, the inner end of the nephridial tubules have lost their connection with the ciliated organ, and the latter has no excretory function, but manufactures coelomic corpuscles.
Development and structure of the teeth in the Dog Fish, Squalus acanthias L. and Scyliorhynus caniculus (L.).
Authors: Kerr T. , Spaul E. A. 
Published: August 2010

SUMMARY.

The development of the teeth of Squalus and Scyliorhynus has been examined in an attempt to clarify various aspects of their detailed structure and to provide a basis for comparison with other vertebrate teeth.
The enamel layer of the tooth is completely formed before calcification begins as a characteristic tissue, composed of a matrix penetrated by long cytoplasmic processes from the pulp cells and by reticular fibres passing inwards from the basement membrane. Calcification of the tooth commences in this enamel substance; during the process the matrix and reticulars alter in appearance and the cytoplasmic processes are replaced by fibres. The basement membrane calcifies where fused to the tooth, and the sharp‐edged ridges of the crown appear to be derived from this membrane.
The dentine appears as fibres laid down on the sides of the pulp, its appearance overlapping the beginning of enamel calcification; these intermingle with other fibres forming an irregular boundary fringe in the enamel and both extend upwards to enclose the apex of the pulp. The pulp cells whose processes penetrated the enamel substance become odontoblasts, and as the fibres enclose the pulp the truncated ends of their processes become enclosed in dentinal tubules.
The superficial similarity between the teeth of selacians and of higher types does not extend to the detailed structure of the teeth, and the question of homologies and relationships requires further work for its solution.
The evolution of the Ellobiidae with a discussion on the origin of the Pulmonata.
Authors: Morton J. E. , Graham Alastair 
Published: August 2010

SUMMARY.The primitive phonate family, the Ellobiidae, is discussed with reference to the structure, ecology and relationships of the following genera—Pythia, Ophicardelus, Cassidula, Ovatella, Leucophytia, Ellobium, Pedipes, Leuconopsis, Marinula, Rangitotoa, MelampusandCarychium. Ecologically, the family is shown to fall into four sections, a more primitive estuarine section, and sections containing marine intertidal, coastal terrestrial and inland terrestrial genera of rather more specialized character. In relation with detailed descriptions about to be published of the functional morphology of British ellobiids, a wider comparative account is now given of the digestive system and the genital ducts, and their evolution throughout the family. Further trends, chiefly concerning the adult and embryonic shell, are dealt with, in a discussion of the evolutionary pattern of the Ellobiidae. The frequent occurrence of parallel evolution, and the relative absence of adaptive radiation, or characters of obvious selective value, are noted. A scheme is proposed for the classification of ellobiid genera into subfamilies, which in some points departs from that of Thiele, based on radular studies by Odhner.A wider review is then given of the evolutionary significance of the Ellobiidae, with reference both to the evolution of pulmonates from prosobranchs, and to their relationships with primitive tectibranchs. Finally, the relationships of the Basommatophora and the Stylommatophora are discussed, and the significance of the Ellobiidae is pointed out, with reference to the origins of both groups. The Basommatophora are held to be a phylogenetically unnatural group. The Ellobiidae is the only family of this group that could have provided possible ancestors for Stylommatophora, and these are unlikely to have occurred among known genera. Reference is made to the geological evidence in support of the view of gastropod evolution presented from this study.
The skull of the toad, Hemipipa carvalhoi Mir.‐Rib. with remarks on other Pipidae.
Authors: Paterson Nellie F. 
Published: August 2010

SUMMARY.An account is given of the morphology of the head region of Hemipipu carvalhoi excluding the nasal cavities which were discussed in a previous publication (Paterson, 1951).The markedly fenestrated cartilaginous nasal capsule closely resembles that of Pipa and also shows similarities to that of Hymemhirus. In Xenopus. however, the nasal region is better chondrified and approximates that of other Salientia.The nasals and frontoparietals are large, the latter being fused and provided with a conspicuous supraorbital ridge which also features in Pipa and Hymemchirus.There is no quadrato‐jugal, palatine or prevomer and the squamosal lacks the processus zygomaticus that occurs in Xempus.The ventral surface is largely occupied by the broad parasphenoid, while the pterygoid, in common with that of Pipa and Xenopus, is provided with an anterior process projecting forward towards the posterior end of the maxilla.There is a continuous cartilaginous subocular arch from the quadrate to the planum antorbitale.Only three foramina occur in the medial wall of the membranous labyrinth. These have been determined as the foramen endolymphaticum, the foramen perilymphaticum superius and a single foramen acusticum.The quadrate is massive and mainly cartilaginous. It is concluded that in the Pipidae a pseudobasal process developed from the larval palatoquadrate is connected to a basicranial ridge of the neurocranium by means of a post‐palatine commissure. The latter, which is regarded as belonging to the neurocranium, is probably comparable to the auditory ledge described in other Salientia.The sound‐conducting apparatus is essentially similar to that of other Pipidae, but lacks the small operculum that obtains in Xempus.Although the complete hyoid apparatus was not investigated, it is evident that the adult Hemipipa agrees with Pipa in the absence of ceratohyals.
Gut haems in the invertebrates.
Authors: Phear Elizabeth A. , Fox H. Munro 
Published: August 2010

SUMMARY.

A survey has shown that protohaemochromogens in the gut lumen are widely distributed in Mollusca and Polychaeta, but are not widespread in Crustacea. These compounds were always found in highest concentration in the anterior part of the gut.
All the Polychaeta examined, with the exception of two species of Chaetopteridae, were found to have a gut protohaem compound, and in several species this was shown to be methaemoglobin, or an undentified compound which may have been haematin but was not 2 haemochromogen. Haemochromogens were of more frequent occurrence in tubicolous than in free‐living Polychaeta.
In several species of Polychaeta an inverse correlation was established between the concentration of gut haem (as haemochromogen or unidentified haem) and that of the respiratory pigment in the blood (whether haemoglobin or chlorocruorin).
The survey has given no indication of the factors governing the presence or the nature of the particular haem compound in the gut, but there is evidence that these compounds are derived from the tissues of the animal in which they are found rather than from the food.
The variation in the concentration of haemochromogen in the gut of Helix aspersa and Daphnia magna has been studied in the field and in the laboratory.
The concentration has been found to vary little with the nature of the food, although in Daphnia an external factor of unknown nature has been found to be necessary for the maintenance of a high concentration in mature animals.
The amount of helicorubin in the crop of Helix has been shown to vary with the activity of the animals, and with the state of digestion of the food.
Evidence has been put forward that helicorubin is reabsorbed from the gut of Helix, and that it is not lost from the body.
The amount of daphniarubin in the anterior part of the gut of Daphnia has been found to vary with the activity of the gut, but the chief cause of variation is the concentration of body haem. Direct and inverse correlations with the haemoglobin concentration in the blood have been established under different conditions.
On the lancelets of West Africa.
Authors: Webb J. E. 
Published: August 2010

SUMMARY.

During 1948–1952 a large number of small terrestial mammals were collected in connexion with Scrub‐Typhus investigations.
Simple standard data of weight and state of fertility of these animals were kept, and the results are summarized in table 15.
With a few exceptions, the sex ratio approximated to equality. Of the exceptions, most could be shown to be due to bias in collecting. In a few species particularly associated with man, however, there was an apparent loss of males in the higher weight groups, suggesting a higher death rate among males. In the house mouse, Mus musculus, however, there was an excess of males.
Males showed a distinct annual variation in the fertility and weight of testes. Forest rats showed an increase in fertility during the middle of the year, but the house shrew, Suncus murinus, showed a cycle of reverse phase. The variation did not appear to be great enough to affect breeding.
The mean weight of the males at the onset of fertility was calculated from the regression of percentage‐fertile on body‐weight, with scales suitably adjusted.
Females showed a slight annual variation in pregnancy rate too slight to delimit any breeding seasons. The mean weight at onset of pregnancy was similarly estimated.
The numbers of embryos were recorded and used to calculate a mean embryo number. Combined with the pregnancy rates this gave an estimate of the reproduction rate.
Data on the reproduction of some Malayan mammals.
Authors: Harrison J. L. 
Published: August 2010

SUMMARY.1. During 1948–1952 a large number of small terrestial mammals were collected in connexion with Scrub‐Typhus investigations.2. Simple standard data of weight and state of fertility of these animals were kept, and the results are summarized in table 15.3. With a few exceptions, the sex ratio approximated to equality. Of the exceptions, most could be shown to be due to bias in collecting. In a few species particularly associated with man, however, there was an apparent loss of males in the higher weight groups, suggesting a higher death rate among males. In the house mouse, Mus musculus, however, there was an excess of males.4. Males showed a distinct annual variation in the fertility and weight of testes. Forest rats showed an increase in fertility during the middle of the year, but the house shrew, Suncus murinus, showed a cycle of reverse phase. The variation did not appear to be great enough to affect breeding.5. The mean weight of the males at the onset of fertility was calculated from the regression of percentage‐fertile on body‐weight, with scales suitably adjusted.6. Females showed a slight annual variation in pregnancy rate too slight to delimit any breeding seasons. The mean weight at onset of pregnancy was similarly estimated.7. The numbers of embryos were recorded and used to calculate a mean embryo number. Combined with the pregnancy rates this gave an estimate of the reproduction rate.
A new type of web spun by spiders of the genusUlesaniswith the description of two new species
Authors: Marples B. J. , Mattaews L. Harrison 
Published: August 2010

SummaryA new type of spring web, spun by spiders of the genusUlesanisof the Theridiidae, is described. It consists of a straight or Y‐shaped sticky thread. The spider holds one end of the thread in one foot and sits on a twig. When prey is caught it releases the twig and allows the thread to go slack. This behaviour affords a close parallel to the single‐thread cribellated web ofMiagrammopes.Two new species ofUlesanis, U. pukeiwa and U. puketoru, are described from New Zealand, and they are compared with other Australasian and Pacific species.
The mouth‐parts of the Down‐looker fly, Rhagio (=Leptis) scolopacea (L.) Diptera, Rhagionidae)
Authors: Bletchly J. D. , Varley G. C. 
Published: August 2010

Summary.A detailed account is given of the anatomy of the mouth‐parts of Rhagio scolopacea (L.) (Rhagionidae) and some comparisons made with earlier studies of Scopeuma stercoraria (L.) (Cordyluridae) and Empis livida (L.) (Empididae). The probable movements and functions of the mouth‐parts are deduced and the morphological adaptations to these discussed and compared in a similar manner. Rhagio shows no predatory adaptations and is possibly a nectar feeder. Homologies are traced including that of the maxilla and a general discussion on homology, with special relation to particular problems in these three species, is included.
THE FOSSIL CARNIVORES OF THE TRANSVAAL CAVES: CANIDAE
Authors: EWER R. F. 
Published: August 2010

SUMMARYThe whole of the fossil canid material at present available from the Transvaal caves has been examined. Canis terblanchei (Broom) is considered to be a valid species, but the type specimen does not come from the Kromdraai deposit, as Broom originally stated. This species has not been found at any of the three main deposits, but at least one additional specimen lias been found at the site known as Coopers.A new species, Canis brevirostris, is described from the Sterkfontein type site. This species does not resemble either of the living South African jackals, and it has not been found at Swartkrans or Kromdraai.A large number of specimens, including material from all the three main sites, is considered to belong to a form differing only slightly from the living Canis mesomelas. Although the material may be somewhat heterogeneous it has not been found possible to sub‐divide it, and all the specimens have been referred to a subspecies of the living form which has been named Canis mesomelas pappos.The position of Canis antiquus (Broom) remains undecided.A mandibular fragment from Swartkrans is provisionally referred to Vulpes pulcher Broom.
SEXUAL DIFFERENCES IN THE DIMENSIONS OF THE MILK TEETH OF THE CHIMPANZEE AND GORILLA
Authors: ASHTON E. H. 
Published: August 2010

SUMMARY

Comparisons have been made between fifty‐eight dimensions of the milk teeth of (a) the male and female chimpanzee, (b) the male and female gorilla.
There is no evidence that the milk teeth of the male chimpanzee differ in size from those of the female.
The milk teeth of the male gorilla are, on the average, 3 per cent bigger than those of the female.
These differences appear before the hormonal factors responsible for the pubertal growth spurt become operative, and may be controlled genetically.
THE STRUCTURE AND FUNCTION OF THE POST‐ABDOMEN OF CAMPTOCERCUS (CRUSTACEA: CLADOCERA)
Authors: GREEN J. 
Published: August 2010

SUMMARY Camptocercus lilljeborgi has a long, extremely motile post‐abdomen. The movements of the post‐abdomen keep the carapace free from epibionts, keep the food groove between the thoracic limbs clear, and may be of use in escaping from certain small predators. There is a complex joint between the abdomen and post‐abdomen. The muscles moving the post‐abdomen are described and homologized with those of Eurycercus lamellatus and Daphnia magna.
REPRODUCTION IN THE ORKNEY VOLE (MICROTUS ORCADENSIS), UNDER A SIX‐HOUR DAY‐LENGTH AND OTHER CONDITIONS
Authors: MARSHALL A. J. , WILKINSON O. 
Published: August 2010

SUMMARY

There is no significant difference between the reproduction rates of laboratory populations of Orkney Island Voles (Microtus orcadensis) existing under (a) winter day‐length (six hours) and (b) London summer day‐lengths (fifteen hours to fifteen hours twenty‐eight minutes) if abundant food is provided at ordinary such summer temperatures.
These data, and other considerations discussed, suggest that, as in birds, environmental factors other than photoperiodicity alone, probably govern the sexual cycle of some mammals.
A grouped arrangement of interstitial cells essentially similar to that occurring in birds is described. As spermatogenesis proceeds these cells expend their cholesterol‐positive lipids as do those of birds.
The seminiferous tubules do not undergo a post‐nuptial metamorphosis. Even when males are kept alone in total darkness the germ‐cells retain their integrity and do not metamorphose as do those of passerine birds under semidark conditions.