Land-Ckabs.] 



MUSEUM OF ANIMATED NATURE. 



303 



In some respects the genus Pireraela agrees with 

 Xantho, but the external antennae are prolonged, 

 and the stem is many jointed. The Piremela den- 

 tieulata, Fig. 3121, about hah" an inch in length, 

 and of a greenish colour, inhabits our coasts and 

 those of France and Southern Europe. The cara- 

 pace is strongly bossed above. 



Another genus not very remote from Piremela is 

 Thia, of which one species, Thia polita, Fig. 3122, 

 is European. It lives buried in the sand at a small 

 distance from the shore, and is scarcely an inch in 

 length. Its colour is roseate. 



VVe may here notice the genus Eriphia ; in this 

 form the lateral antennse are inserted between the 

 ocular pits, and the median antennae. 



One species, Eriphia spinifrons, Fig. 3123, is very 

 extensively spread, and occurs on the coasts of 

 Europe. Another species, Eriphia Gonagra, Fig. 

 3124, is a native of the coasts of South America. 

 A third species, Eriphia laevimana. Fig. 3125, is a 

 native of the shores of the Isle of France: 



Close to Xantho may be placed the genus Rup- 

 pellia, of which one species, Ruppellia tenax. Fig. 

 3126, is a native of the Red Sea. It is about two 

 inches in length. 



According to Milne Edwards, between Cancer 

 and Xantho may stand the genus Zozymus, of 

 which the Zozymus seneus of the Indian Ocean, 

 Fig. 3127, is an example. This species is about 

 three inches in length, and of a yellowish colour 

 spotted with red. 



There is a very remarkable genus of crabs termed 

 Corystes, in which the exterior antennae are longer 

 than the body, and furnished with two rows of cilia. 

 The anterior limbs in the male are twice as long as 

 the body, and nearly cylindrical ; in the female they 

 are about as long as the body, and compressed, 

 especially at the last joint ; the other feet are ter- 

 mmateJ by an elongated claw pointed and chan- 

 nelled longitudinally. The carapace is oval, with 

 an anterior rostrum. 



The Corystes Cassivelaunus (C. dentatus and C. 

 longimanus, Latr. ; Cancer Cassivelaunus, Pennant) 

 is found on the coasts of England and Fi-ance. The 

 specimens figured by Pennant were dredged up 

 near Holyhead and Ked Wharf, Anglesey, in deep 

 water. Fig. 3128 is the male. Fig. 3129 the female, 

 of this singular crab. The surface of the carapace 

 is somewhat granulous, with two denticles between 

 the eyes, and three sharp points on each side. 



Latreille gave the name of Melia lo a form of 

 Cancerians of which the Melia tesselata is an 

 example. This species, Fig. 3130, is about half an 

 inch m length, and of a whitish colour, with red 

 lines. It is found on the shores of the Isle of 

 France. 



VVe now pass to the genus Elisus of Milne 

 Edwards, a small group, of which the Etisus den- 

 tatus is an example. This species is about four 

 inches in length, and inhabits the seas of the Indian 

 archipelago. The carapace is represented at Fig. 

 3131. 



There are several genera of crabs, constituting a 

 group called Notopods (Notopoda), which have the 

 feet of the fourth and fifth pairs elevated on the 

 back, and not terminated with paddles, and the 

 eyes supported by simple peduncles. To this group 

 belongs the genus Dorippe, Dromia, &c. 



The genus Doiippe has small claws, short and 

 equal; the other feet are long and compressed, the 

 thud pair being the largest ; the two last pair are 

 elevated upon tlie back, and terminated by a small 

 hooked nail, which is folded back upon the next 

 joint. The eyes are small and lateral ; the external 

 antennsE rather long and setaceous. The species 

 are widely distributed, inhabiting the seas of the 

 warmer climates, as the Mediterranean, the Adriatic, 

 and those of Manilla, &c. They seldom visit 

 the shore, but haunt great depths, and it is probable 

 that, as in Dromia, they use the hinder limbs for the 

 purpose of covering themselves with foreign bodies, 

 by way of shelter and concealment. Of their habits, 

 however, very little is known. 



The Dorippe lanala. Fig. 3132, is found in the 

 Mediterranean : the body and limbs are covered 

 with reddish down. It is the Cancer lanatus of Lin- 

 naeus. From the genus Dorippe has been separated 

 that termed Ethusa by M. Roux, and which may 

 be distinguished from the former by the simple 

 character of the orifice leading to the respiratory 

 cavities. In Dorippe, there is on each side at the 

 base of the anterior or claw -limbs, an aperture in 

 the form of a button-hole, oblique, ciliated on its 

 edges, and longitudinally slopped by a diaphragm, 

 which communicates with the branchiae, and serves 

 as an outlet for the water which leaves them. In 

 Ethusa this is a fissure of the ordinary character. The 

 Ethusa Mascarone, Fig. 3133, Irom the Mediter- 

 ranean, is an example. It is the Cancer Mascarone 

 of Herbot. 



The genus Dromia, one of the Notopods, is re- 

 markable for the hirsute character of the limbs and 

 carapace; the claw- limbs are large and strong; the 



fourth and fifth feet are elevated on the back, and 

 the last joint which is bent is opposed to a spine 

 which terminates the penultimate joint. The eyes 

 are small, and rather approximated. The species 

 of this genus are extensively distributed through 

 the seas of the warmer climates ; they are indolent 

 in their habits, and live in spots where the sea is 

 moderately deep, and rocks afford them snug places 

 of refuge. Generally they are found covered with 

 the valves of Conchifera, or with a species of fleshy 

 polype (alcyonium), which they place and secure 

 by means of their posterior limbs, and which mask 

 them from the notice of enemies. The alcyonia, 

 once fixed on the carapace, develop and extend 

 themselves, and at last entirely conceal it. In July 

 the females rouse from their lethargic indolence 

 and betake themselves to the shallows for the pur- 

 pose of depositing their eggs. 



The Dromia hirsutissima, Fig. 3134, is found 

 at the Cape of Good Hope. It is covered with long 

 red hairs. 



Closely allied to Dromia is the genus Dynomene, 

 in which the ocular peduncles are rather elongated, 

 and the two posterior feet only dorsal, and much 

 inferior in size to the other. The carapace is some- 

 what heart-shaped. 



The only recorded example is the Dynomene 

 hispida, a small species covered with hair, and 

 found on the shores of the Isle of Fiance. It is 

 represented at Fig. 313.5. 



We now turn to species more terrestrial in their 

 habits, and capable of living for a considerable 

 time out of water, from which they often wander to 

 great distances. To the groups which display these 

 habits, may be referred the Thelphusians, certain 

 fluviatile crabs, which Milne Edwards regards as 

 constituting a link between the Cancerians and the 

 true land-crabs. In general form they approach Eri- 

 phia ; but they differ in habits, living in the earth 

 about the banks of rivers, or in humid forests. 

 Several species are known. The restricted genus 

 Thelphusa is represented by a species well known 

 in the South of Italy, Greece, Egypt, and Syria ; 

 the Crabe fluviatile of Belon, Thelphusa fluviatilis. 

 Fig. 3136. 



This species, which was well known to the an- 

 cients, and is figured on many of the Sicilian and 

 Grecian medals, is very common on the boidexs of 

 the rivulets, streams, and lakes of the south of Italy, 

 where it makes its burrows. The Greek monks, 

 according to Cuvier, eat it raw, and during Lent it 

 forms one of the dishes of the Italians. Its carapace 

 is about two inches in diameter both transversely 

 and longitudinally. The general colour is pale 

 gray. The upper surface is smooth, with little fur- 

 rows and asperities anteriorly along the sides. The 

 claws are rough, of a reddish brown colour at the 

 extremities; they are long, conical, and unequally 

 dentated : a, the external jaw-foot. Other species 

 are natives of India and Africa. 



An allied genus, Boscia, presents us with a species 

 (the only one known) from the Antilles and South 

 America. Like the Thelphusa, it is terrestrial, 

 making burrows along the banks of rivers. M. 

 Milne Edwards states that a dissection of an indi- 

 vidual well preserved in spirit, by M. Audouin and 

 himself, discovered to them a very remarkable dis- 

 position of the branchial apparatus of this crustacean. 

 The cavities which enclose the breathing organs are 

 elevated far above the upper surface of the bran- 

 chiae, and present a great vacant space, the walls of 

 which are lined with a tomentose membrane, found 

 to be covered with vegetation. The extensive 

 branchial cavities are most probably intended in 

 this crab for containing a due supply of water for 

 laving the branchiae ; but with respect to the vege- 

 tation noticed by MM. Milne Edwards and Audouin, 

 it appears to us to have been accidental ; it 

 is however an interesting circumstance, and one 

 out of many examples in which parasitic vegetation 

 has been found to become developed in or upon 

 living animal bodies. Fi^. 3137 represents the 

 Boscia dentata, about a third of the natural size. 

 a, the antennary margin of the carapace ; h, the ex- 

 ternal foot-jaw. 



We may now refer to a group of land-crabs 

 termed Ocypodians, remarkable for their extreme 

 rapidity, which is such, says Cuvier, that a horseman 

 has some difficulty in overtaking them ; hence the 

 term ' cavalier ' which the older naturalists applied 

 to them. They live in burrows which they ex- 

 cavate in the sand or along the margin of the 

 shore. 



The carapace is rhomboidal and much elevated 

 anteriorly. The eyes are long ; the cornea generally 

 laige and transparent. The anterior limbs are ge- 

 nerally very compressed, and of unequal size ; the 

 rest are long, and often terminate in compressed 

 points. 



In the restricted genus Ocypoda, the cornea is 

 transparent and very large, of an oval figure, occu- 

 pying at least the half of the length of the ocular 

 peduncles, and commencing very near the base of 



those stems. The orbital furrows are very large, but 

 not deep. In the male the difference in size be- 

 tween the anterior or claw-iimbs of each side is very 

 considerable ; in the female, it is less striking. 

 The species are widely distributed. One, the Ocy- 

 poda Hippea, inhabits the coasts of Syria, and tlie 

 Mediterranean borders of Africa. It is distinguished 

 by a tuft of hairs, which terminates the ocular pe- 

 duncles. Other species are Indian and American. 



Fig. 3138 represents the Ocypoda arenaiia, or 

 Sand Crab of Catesby ; a native of the coasts of 

 North America and the Antilles, a, the under side 

 of the head. 



The habitsof this species are very singular. During 

 the whole of the summer months, it lives on the 

 shore, excavating for itself a burrow three or four 

 feet in depth, above the line of the highest tides or 

 dash of the waves. In this retreat it secludes itself 

 during the day, coming abroad on the approach of 

 dusk to seek for food — it traverses the shore very 

 nimbly, and when pursued darts away with great 

 velocity, at the same time elevating its claws by 

 way of menace. On the approach of winter, or 

 towards the end of October, troops of these crabs 

 leave the sea-side, and march inland, till, arriving at 

 some suitable spot, they dig deep holes like those 

 along the shore, for the purpose of hybernation. 

 Into these they enter, stopping up the entrance with 

 such address, that no trace of excavation is left. 

 They then retire to the bottom, and remain quiescent, 

 till the return of spring, when, animated by the 

 warm weather, they emerge from their dormitories, 

 retrace their steps to the sea-side, and set about re- 

 pairing their old dwellings. 



Certain species of the genus Ocypoda, as we have 

 said, carry a tuft of hairs at the extremity of their 

 ocular peduncles ; others, an appendage in the form 

 of a tubercle, cylinder, or stylet, which overpasses 

 the transparent cornea. We mentioned the Ocy- 

 poda hippea of Northern Africa as an example, its 

 ocular peduncles being tufted. Fig. 3139 repre- 

 sents this curious species, a, the claw ; h, the under 

 surface of the male. 



The next genus of the Ocypodians is Gelasimu.s. 

 In this form, the cornea is very small and rounded, 

 and seated at the top of a long peduncle. In the 

 femalesthe anterior or claw-limbs are very small, but 

 in the males one is enormously developed, while the 

 other remains undeveloped, being in fact shorter and 

 more feeble than the succeeding limbs. It is some- 

 times the light and sometimes the left of the anterior 

 limbs which becomes enlarged, often indeed to such 

 a magnitude as to make the body appear trifling in 

 comparison. It appears that some of the species 

 have at a certain age, if not always, a stylet at the 

 extremity of the ocular peduncle, on the side of the 

 great claw, whilst the eye on the side of the unde- 

 veloped claw always retains its ordinary form. 



The Gelasimi are found in the warm countries of 

 both hemispheres ; they live on the sea shore, or on 

 the borders of saline marshes, and burrow deep cy- 

 lindrical holes running obliquely downwards, and 

 often so close together, and in such numbers, as to 

 form a sort of crab-warren. Each burrow is tenanted 

 by a pair of these crabs, and the male keeps guard, 

 closing the entrance with its great claw. While 

 running over the ground, these crustaceans usually 

 keep the large claw elevated before the body, as if 

 making a signal in order to call to some one, and 

 from this habit they have obtained the name of 

 callers or beckoners, 'Criibes appellants.' The spe- 

 cies are very numerous, but like the Ocypoda they 

 are diflicult to be distinguished, because the parts 

 which differ the most, namely the front and the 

 great claw, change their form with the progressive 

 age of the animal. One species observed in South 

 Carolina by M. Bosc, passes the three winter months 

 in its retreat, and does not seek the water until the 

 period of depositing its eggs. 



Fig. 3140 represents the Gelasimus annulipes from 

 the Indian Seas, n, the under side of the head ; b, 

 the abdomen ; c, one of the antennae. 



Fig. 3141 represents the Gelasimus Marionis, from 

 Manilla. 



Like the species of the restricted genus Ocypoda, 

 the Gelasimi are singularly rapid, traversing the 

 shore with such celerity that it is by no means an 

 easy thing to overtake them ; nor are they incapable 

 of defence, as may be readily conceived from the 

 magnitude of the great claw, which is extremely 

 powerful, and well adapted for inflicting a severe 

 gripe with the pincers, or even a lacerated wound, 

 the serrations of the opposed edges being very 

 sharp. 



We may now advance to a group of land crabs 

 termed the Gecarcinians, known to the French unde- 

 various names, as Toulouroux, CrSbes peints, ana 

 Crabes violets, &c. 



The Gecarcinians are, as it would appear, even 

 more exclusively terrestrial than the Ocypcidians, 

 and so decidedly organized are the branchiae for 

 aerial respiration, that if submerged for any length 

 of time in the sea, the animals perish from suflb- 



