..

A•..r 6k- 44---'44.

•-

OF

THE

ACADEMY OF NATURAL SCIENCES

OF PHILADELPHIA.

VOL. VI.

1852 7 1853.

PHILADELPHIA.
PRINTED FOR

THE ACADEMY,

By Merrihew do Thompson, Merchant street, above Fourth,

1854.

6

[JANuArtY,

have inhabited this continent, and as in the existing creation Dicotyles is the true
equivalent of Sus in America, the probability of our very distinct fossil species
belonging to Dicotyles is much increased; this probability is rendered almost
certain, when we consider that remains of true Dicotyles have been found in
Illinois in company with other singular forms, (Platygonus and Anomodon) whichby their great peculiarities would seem to indicate a period anterior to that of
the Mastodon.
The measurements of the canine are : length of enamelled surface along anterior
curvature 2.2 ; breadth of posterior surface .37 : radius of curvature of posterioredge 2.0; of anterior edge 2.1.

The Committee to which was referred Mr. Dana's papers on the Crustacea of the Exploring Expedition, reported in favor of publication in theProceedings.
Conspectus Crostaceorum, ctc. Conspectus of the Crustacea of the Exploring
Expedition under Capt. Wilkes, U. S. N. By JAMES D. DANA.
PAGURIDEA, continued) and Subtribe MEGALOPIDEA.
I. PAGTJRIDEA, continued.
Among the species of the genus Pagurus, as restricted in my former paper on
the Paguridea, there are still three groups of distinct character ; one, having no
trace of a beak, the front being truncate, and also having the fingers opening in a
vertical plane, the hands being usually compressed, with commonly the left thelarger; a second, having a short beak or triangular point in front, and the fingers
opening like the preceding, with the hands subequal ; a third, having a beak likethe last, but the fingers opening in a horizontal plane, the hands being subequaland more or less depressed, and never compressed. The first group has Paguruspunctulatus for its type ; the second, P. aniculus ; the third, 1'. clibanarius.
They form three genera with the following characters :1. PAGURUs.—Frons non rostratus, truncatus. Manus antice sepius cornpressw, interdum submqum, smpius sinistra majore, digitis apice corneis, in pianoverticali claudentibus.
2. ANICULUS) D.—Frons triangulate rostratus. Manus antic submquw,
digitis apice corneis, in piano verticali claudentibus.
3. CLIBANARIUS, D.—Frons triangulate rostratus. Manus anticm subaqua,plus minusve depressx, digitis apice corneis, in piano horizontali claudentibus.
Species P. cequalis, zebral ltumilis, globosi-manus, Clibanario pertinent.
The species Pagurus aniculus may hereafter be named Aniculus typiens ; theP. clibanarius, Clibanarius vulgaris; and the P. Bernhardus, Bernhardus sod,lonyx. The name Bernhardus pubescens, (see preceding volume, p. 270,) we
propose to change to B. scabricultts, as Kroyers has described a Pagurus pubescens, which is probably a Bernhardus.
Descriptiones Pagmrideorum adhuc inedita.
BERNHARDUS OBESI-CARPUS.—Frons medio prominulus, obtusus. Regio carapacis antica paulo transversa, nudiuscula. Oculi crassi et perbreves, aciculo
longiores, squamCi basali ovata, subacuta, integra. Antennae externze nudes,
basi multo longiore quarn oculus, aciculo crasso, brevi, apicem articuli 3tii
attingente. Pedes toti fere nudi et granulosi, non armati ; antici inmqui; manu
majore oblonga., convexa, symmetrica, granulis nitidis partim seriatis, carpo
multo crassiore, payee latiore. Pares 2di et 3tii crassiusculi, articulo 3tio supra* Tidsk. ii, 251, 252.

7

1852.]

scabri-rugato et breviter hirsute, tarso curvato, canaliculato. Hab. Valparaiso ?
Long. 2".
BERNHARDUS 1EQUIMANUS.—Carapax sparsim pilosus, regione antica non oblonga, fronte ad medium angulato, vix rostrato. Oculi cylindrici, aciculum antennalem longitudine aquantes, squama basali apice products et 3-4 -denticulate.
Antennarum externarum flagellum infra elongate ciliatum. Pedes superficie
granulati partim sparsim hirsuti, marginibus hirti ; antici ;aqui, mediocres, manu
breviter elliptica, parce latiore et longiore quam carpus, non costata, marginibus
subspinulosis, carpo supra subspinuloso et hirto. Pedum 4 sequentium tarsi
bene canaliculati, infra ciliati. Hab. Valparaiso. Long. 1k".
BERNHARDUS CRINITICORNIS.—Frons medio parce angulatus. Regio carapacis
antica non transversa. Oculi mediocres, aciculo antennali paulo longiores,
squama basali apicem rotundata. Flagellum antennarum externarum infra criniturn non ciliatum. Pedes antici valde inaequi, nudiusculi, manu majore oblonga,
paulo longiore et latiore quam carpus, scabricula, spinulis subtilissimis 4-5-seriatis, margine inferiore fere recto, carpo minute spinuloso. Pedes 2di •3tii laxe
pubescentes, non spinulosi, tarso non canaliculato. Hab. portu ‘4 Rio Janeiro."Long. 9-10m.
PAGURUS EUOPSIS.—P . punctulato affinis. Oculi fronte carapacis valde longiores, crassiusculi. Flagellum antennarum externarum nudum, articulis versus
antenna extremitatem latere interne gibbosis ; aciculum parvulum. Pedes antici
sat inaqui, manu majore carpoque oblongis, extus spinulosis et hirsutis. Pedes
2di 3tii marginibus multo hirsuti, articulo 5to spinulis supra paulo armati, tarsis
totis subteretibus, undique divaricata hirsutis. Bab. ad insulam "Upolu" et infreto "Balabac." Long. 2i".
CLIBANAR1US STRIOLATUS.—Regio carapacis antica fere quadrata. Oculi
graciles, margine carapacis antico vix breviores, squama basali angusta, acuminate, bidentata. Pedes antici subaqui, manubus brevibus carpisque supraspini-tuberculatis et pilosis, manu sinistra maxis paulo majore. Pedes 2di 3tii
supra infraque paulo hirsuti, multis lineis brunneis longitudinalibus ornati, tarso
subterete, non breviore quam articulus penultimus, sinistro 3tii paris articulo
5to extus parce convexo, acie rectangulata superne instructo. Hab. insula
66 Tongatabu," et archipelago 66 VAL "Long. 2"1. Paguro lincato, Edw. propinquus.
CLIBANARIUS BRASILIENSIS.—Regio carapacis antica paulo oblonga. Rostrum
bene triangulatum. Oculi gracillimi, margine carapacis antico non breviores,
squama basali valde truncata et brevissima, pilis longis, margine apicali transverse
instructs. Pedes antici aqui, manu dextra parce majore. Pedes. 2di 3tiiquepersparsim hirsuti, subnudi, tarso perbrevi, articulo 5to paris 3tii extus subcomplanato, parce convexo, supra subcarinato. Pedes colore
Hab. portu "Rio Janeiro." Long. 11".
Clibanarius globosi-manus (Pag. globosi-manus, D.) P. corallino, Edw. adhuc
partim descripto an differt ? In specimine globosi-mani non attrita, pedes
2di 3tii marginibus hirsuti non nudiusculi. Clibanariis aliis totis nobis lectis
differt, supeficie externs articuli 5ti sinistri paris 3tii omnino hirsute.
II. MEGALOPIDEA.
The question of the maturity or immaturity of the Megalopm and that of theirtrue place in the natural system, still remain in doubt. Without touching onthese points, at this time, I propose to describe some new genera and species
pertaining to the group.
The species, however diverse, agree in the structure of the abdomen and its
caudal appendages ; in the position of the four antenna between the eyes ; in thearticulations of the outer antenna; in the inner antenna folded longitudinally orobliquely either side of the beak ; in the general form of the outer maxillipeds ;in the large size and lateral position of the eyes without orbits; in the general
structure of the legs; and in their habits. The beak is either horizontal or[JANUARY)

8flexed downward, and has usually a sharp prominent tooth either side of it,
exterior to the inner antennae.
The genus Megalopa, Leach, as now accepted, embraces two distinct sets ofspecies—the M. Montagui and armata for which it was instituted by Leach,and the M. mutica of Desmarest. The former (the true Megalopw) have thebeak nearly horizontal, with rarely a tooth either side, and there is a reflexed
spine on the ventral surface of the first joint of the 8 posterior legs. The latterhas the beak bent downward vertically, and either side of it there is a prominent
spine or tooth; the ventral surface of the base of the legs is unarmed. The M.
mutica is very closely related to Monolepis spinitarsys of Say, the only difference being that the extremity of the posterior legs in this species of Monolepis
bear 3 or 4 seta✓ rather longer than the tarsus, while the descriptions of the
mutica make mention of no such set . The posterior legs in Monolepis fold up
and overlie the carapax : but these legs are otherwise like the preceding, thoughsomewhat smaller, and it is probable that this habit in the M. mutica has been
overlooked, as these animals almost always swim with the posterior legs extended like the others, when taken and kept in a jar for examination, and theyalso have them extended when walking. These legs do not resemble at all theposterior pair in Porcellana or Galatha. I had examined several species before
I discovered this habit with regard to the posterior legs. The animal also throws
the fourth pair of legs forward along or over the borders of the carapax, so thatthe extremity overlies the bases of the eyes and the tarsi hang down in front ;and at the same time the two preceding pair are folded up and lie against thesides of the carapax outside of the 4th pair, or the 3d pair may be thrown forward like the 4th. A Sooloo species, and another common off Cape of Good
Hope, were observed swimming with the legs thus disposed.
Say's genus Monolepis* also embraces two groups, alike in the deflexed front
and the longish setae at the extremity of the posterior tarsi. In one division,
including the M. inermis, the tarsi are flattened styliform, and unarmed, witheither lateral edge sparsely furnished with minute hairs ; the fossa of the sternum,
along which the abdomen lies when inflexed, has a prominent trenchant border ;the depression on the carapax for the posterior legs is rather abrupt and somewhat neatly defined ; the body is very convex and obese, with the sides high andvertical, and much wider behind than before, being gradually narrowed forward.
The other division has the tarsi unguiform, compressed, and spinous below, theantepenult spine always longest ; the fossa of the sternum with fl aring borders;the depression of the carapax for the posterior legs shallow concave ; the bodymore flattened above, with the sides more oblique. This division corresponds
to Monolepis spinitarsus.
Besides the preceding, there is another group of Megalopidea, examined by theauthor, resembling Megalopa of Leach, except that the tarsus of the posteriorlegs is narrow lamellar instead of unguiculate, and edged with longish setae
somewhat shorter than the tarsus.
There is still another group in which the front is horizontal and tricuspidate,the inner antennae when retracted being exposed in the interval between the beakor inner cusp and either outer, lying in view as in Plagusia.
With these explanations we give the characters of the genera.
1. MONOLEPIS, Say .—Carapax fronte tricuspidatus sed valde deflexus ideoquefrons superne visus medio non acutus sed truncates. Pedes 5ti minores, super
carapacem sxpe restantes, depressione ad eos recipiendos abrupta, tarsis inermibus, depress's styliformibus, paris postici non depressis, apice 3-4 setis longiusculis (tarso paulo longioribus) instruct°. Sterni fossa abdominalis marginibus
bene prominens et subacuta.—Monolepis inermis, Say, typus est.
2. MARESTIA, Dana.—Carapax fronte uti in Biono/epi. Pedes 8 postici adbasin infra non armati ; 5ti minores, super carapacem sxpe restantes, depressione
ad eos recipiendos parce concaves ; tarsis styliformibus, unguiculatis, spinis infra
Journ. Acad. Nat. Sci., Pliilad., i. 155.

1852.]

9armatis, paris postici apice setis longiusculis instructis.—Typus est M'onolepis
spinitarsus, Say. Hic pertineret quoque Meg. mutica, Desm. si ejus pedes postici
setis longiusculis confecti ; aliter genus alterum instituendum. Verbum " Marestia clarissimum Desmarest commemorat.
3. MEGALOPA, Leach.—Carapax fronte simpliciter rostratus, rostro via
deflexo, acuto. Pedes 8 postici ad basin infra uni-spinigeri 5ti minores, tarso
styliformi.---Typus Meg. Montagui, Leach.*
4. CYLLENE, Dana.—Carapacis frons uti in Megalopa. Pedes 8 postici adbasin infra uni-spinigeri ; 5ti minores, tarso anguste lamellato, setis longiusculis
partim ciliato.
5. TRIBOLA, Dana.—Carapax fronte horizontalis tricuspidatus, rostro (velcuspide mediana) tenui, cuspidibus (vel dentibus) externis vix longiore. Antennm
internee inter rostrum et cuspides externas aperte infiexx. Pedes postici minores,
tarso unguiculato setisque longis non instructo.
Descriptiones IVIegalopideorum adhuc ineditce.
MARESTIA ELEGANS.—Carapax antice angustus et superne visus bilobatus, lateribus fere parallelis, pone oculos vix salientibus. Pedes antici parvi, manu
oblonga, margine inferiore et partim superficie interne remote hirsutis. Pedes
2di marginibus sparsim ciliati, tarso infra 7-spinoso, ad basin tuberculum infra
non gerente. Tarsi postici infra 6-spinosi, apice unguiculati et 4 setis longis
instructi. Hab. Promontorio Bony Spei. Long. Carapacis 4-5"1. An Megalopa
mutica Kraussii (Siidaf. Crust. p. 54) et De Haanii (Faun. Japon. p. 167) ? Sed
pedes postici extremitate setis tarso paulo longioribus instructi.
MARESTIA ATLANTICA.—Carapax antice angustus et superne visus bilobatus,
lateribus postice paulo divergentibus, pone oculos vix salientibus. Pedes antici parvi, manu oblonga, nude aut nudiuscula. Pedes 6 sequentes nudiusculi,
tarso infra quinque spinas tuberculumque ad basin instar calcis gerente.
Tarsi postici parvuli, sed setularurn duabus paribus infra instructi, non spinosi,
apice unguiculati et tribus setis longis armati.—Hab. lat. aust. 6°, long. occ. 24g.
MARESTIA PERVALIDA.—Carapax antice latus et superne visus obsolete quadrilobatus, lobis subxquis, lateribus postice non divergentibus, prope medium unidentatis. Pedes antici pervalidi, menu valde crassa, tumida. Tarsi postici
infra spinosi, apice tribus setis longiusculis armati.—Hab. lat. bor. 6°, long.
orient. 173°.
MONOLEPIS ORIENTALIS.—Sterni segmenta fossam sterni includentia antica margine interiore fere truncata, vix triangulate; segmenta proxima convexa, non tuberculigera. Tuberculus medianus inter aream buccalem et fossam sterni simpliciter subtriangulatus, antice acutus, postice hemisphericus, utrinque depressionedeinde septo brevi antice et oblique producto cinctus. Tarsus pedis postici
brevis, non unguiculatus, apice tribus setis longiusculis armatus, infra setulis
paucis perbrevibus necque spinis instructus. Hab. in mari Suluensi. Long.
carapacis 4"'.—M. inermis differt, sterni segmentis anticis intus non subtruncatis
sed prominenter triangulatis, proximis unituberculatis, tuberculo mediano interarearn buccalem et fossam sterni tuberculis tribus composito.f
CYLLENE HYALINA.—Rostrum parce prorninens. Carapax subovatus, lateribus
pone oculos paulo saliens, postice inermis. Thorax infra ad extremitatem pos* Malac. Pod. Brit. pl. 16. Leach describes three other species, (not noticed by
Edwards,) in Tuckey's Exped. to the Zaire, (London, 1818,) p. 404. The .M.
Cranchii may be a true Megalopa ; the others have a deflexed beak.
t The author is indebted to Prof. L. R. Gibbes, of Charleston, S. C., for theprivilege of examining specimens of the .71/. inermis. They were obtained by himfrom the stomach of a fish off the Atlantic coast between New York and Charleston,in 1846. See Rep. Crust. in U. S. Collections, by Prof. Gibbes, in Proc. Amer.
Assoc. Charleston, 1850, vol.
p. 192.

2

10[JANUARY,

teriorem inermis. Pedes antici mediocres, carpo inermi, manu paulo tumida,
supra subgibbosa, digitis hiantibus, apice inflexis et acutis. Pedes 2di 3tii
4tique subxqui, tarsis fere rectis, longis, articulo penultimo longioribus. Hab.
in mari Atlantico juxta " Rio Negro" Patagonize, et in mari Pacifico prope
cc Valparaiso." Long. carapacis 3-4/".
CYLLENE FURCIGER.—Rostrum elongatum, spiniforme, frontis latitudine nonbrevior. Thorax infra ad extremitatem posteriorem duabus spinis longis divergentibus postice productis armatus. Pedes antici angusti, carpo articuloque
secundo spina brevi curvata armatis, brachio inermi. Tarsi 2di 3tii 4tique parcearmati, styliformes.—Hab in mari Suluensi.
TRIBOLA LATA.—Carapax late ovatus non pubescens, paulo longior quam
latus, lateribus pone oculos parce undulatis, rostro lineari, dentibus frontis lateralibus rostro remotis, apice acutis et paulo divaricatis. Pedes antici parvuli,
tenues, manu pedibus sequentibus vix crassiore. Hab. iii mari Atlantico, prope
insulas " Canary ;" e stomacho piscis " Bonito " lecta. Long. corporis fere
TRIBOLA PITBESCENS.—Carapax oblongus, subovatus, pubescens, lateribus pone
oculos undulatis, rostro lineari, dentibus frontis lateralibus rostro minus remotis.
Pedes toti dense brevissimeque pubescentes ; antici rostrum paulo superantes,
angusti, inaequi, manu dextra non latiore quam carpus. Pedes 8 sequentes fere
duplo longiores, 2dis brevioribus quam 3tii. Hab. in Archipelago "Paumotu "mari Pacifico.

Conspectus of the Crustacea of the Exploring
Conspectus Crustaceorum,
Expedition under Capt. C. Wilkes, U. S. N. By JAMES D. DANA.
MACROURA.
We follow De Haan in placing the genus Galathxa with the Anomoura ; andnear it we arrange YEglea, which widely differs from most other related species
in having penicillate instead of foliose branchiw.
The Macroura, excluding these groups, includes three distinct sections or subtribes.
One, the “Fossores " of authors, or the THALASBINIDEA) has close relations on
one side with the Paguri, and on the other with the Squillidx. They constitutea line of gradation between these extremes, independent mostly of the other
Macroura, and osculating only with the Astaci, although removed from them ingeneral habit and structure. There is a diversity among the legs as to form andposition, which is not found in any other Macroura, and calls to mind the Paguri.
Moreover, there is in general a looseness of structure, a length of abdomen, andsluggish habit of body, unlike the trim compact forms of the typical Macroura.
The anterior feet are thrown directly forward and are thus fitted for the burrowing habits of the species.
The second subtribe—the ASTACIDEA—is composed of the highest grade ofMacroura, approaching in some points of structure the Brachyura. This is seenin the fact that the sides of the carapax fold under and unite to the epistome, as
is well shown in Scyllarus and less perfectly in Astacus ; also in the absence orsmall size of the basal scale of the outer antennm. The Astaci are the transition
species between the other Astacidea and the Caridea, and in the genus Paranephrops, White, the antennary scale is not smaller than is common in the lattergroup. Yet they properly form part of the same section with the Scyllari and
Palinuri, rather than a separate division as made by Milne Edwards; they differ
from all the Caridea in the transverse suture across the carapax near its middle.
The third section—the CARIDEA—includes the typical Macroura, which havethe sides of the carapax not soldered to the epistome, and a large basal scale tothe outer antenna=.** The Curew would constitute another section—Cumidea—if mature animals. But
according to recent researches of Prof. Agassiz, as he has informed the author, they
are in some cases, and probably in all, immature forms of Palwmon, Crangon, andother known Macroural genera.