418 CRUSTACEA. 



Tlie best known species (Cancer lairo, Linn.) inhaljit:^ tlie Isle of Frniicc ; and, ncrrirding" to a native tradition, 

 it feeds upon the fruit of the cocoa-nut, making its excursions daring the night. [It is of largt; size, and is called 

 the Puise Crab. Mr. Cuming found it in abundance in Lord Hood's Island in the Pacilic, living at the roots of 

 trees. Messrs. Quoy and Gaiinard fed this species for many months on cocoa-nuts ; and Mr. CaMiiiii,'-discu\ercd 

 that it climbs the Plaianus odoraiissima, to feed upon the small nats of that tree.] 



In the Hermit Crabs {Parjurus, Fabr.), the four hind-leg's are much smallc-r than the preceding', \vilh tlie claws 

 covei'ed with small tubercles. The tail is soft, long, cylindrical, narrowed at the tip, and unly furnished ^\ith one 

 row of filiform, oviferous appendages. The thorax is ovoid or oblong. 



With the exception of some supei-ficiaUy-known species which live in sponges, serpulae, alcyons, &c., all the 

 others live in univalve shells, of which they close the mouth with their fore-legs and one of their cla\v.i, which is 

 lar;;er than the others. It is stated that the females deposit their eggs two or three times in a year. 



[The manoeuvres of the native species, when they have outgrown their habitations, are quite ludicrous. Cranling 

 slowly along the line of empty shells, &c., left by the last wave, and unwilling to part with their now incom- 

 modious domicile until another is obtained, they carefully examine, one by one, the shells which lie in their way, 

 slipping their tails out of the ohl house into the new one, and again betaking themselves to tiie old one, if this 

 should not suit. In this manner they proceed until thev have found a habitation to their liking. They feed upon 

 dead fish, and all kinds of garbage thrown on the shore ; and, wht-n alarmed, they draw themselves closely into 

 the shell, closing the aperture so firmly, by placing their claws over the entrance, that it is next to impossible to 

 extract them without breakir.g the shell to pieces.] 



Some species, forming the subgenus Co>nobita, Latr., are distinguished by the antennse stretched forward, the 

 intermediate pair being nearly as long as the lateral ones ; the thorax ovoid, conical, narrow, elongated, and very 

 much compressed at the sides. These lodge in land-shells on the rocks of the coasts, rolling down, with their 

 houses, in moments of danger. The other species, forming the most numerous subgenus, Pfl</«;7w, have the inter- 

 mediate antenna: short and bi;nt, ^vith two short filaments. The front dnision of the thorax is square, or reversed 

 triangular- 



Cancer Bernhardiis, Linn. {Pai/iirus s(rch/o)it/.x\ Leach), is xcvy common on the coai-its throughout Europe. It is 

 of a moderate size. Its two fore-legs are armed with points, with the claws nearly heart-shaped, that on the right- 

 hand side being the largest. Pog. Faujasii, Desmarest, a fossil species, approaches it very closely. 



Another species from the Mediterranean differs from the rest in many characters, and forms the subgenus 

 Prophijlax, Latr. The tail is coriaceous, linear, and only curved at the tip ; and it has two rows of subabdominal 

 appendages. Probably the species which live in serpukc, alcyons, &c., such as Pagurm tuhularis, Fabr., belong 

 to this subgenus.* 



In all tlie sul)sequent Macroura. the two posterior legs alone are smaller than the preceding. The 

 subabdominal a])pendages are generally five pairs. The teguments are crustaceous. The lateral appen- 

 dages of the penultimate segments form a fan-hke swimmeret in conjunction >vith the terminal one. 



The two following sections have a character in common, "which separates them fiom the fourth, or 

 that of the Carides. The antennse are inb.erted [in aline] at the same height, the peduncle of the 

 lateral pair hoing never entirely covered Ijv the ^cale when present. Often there are only four pairs of 

 the false suhahdumiual fci't. The intcrmrihate antenna; are never terminaTnl by two threads: thev 

 arc ordinarily b>liortcr, or scarcely as lung as their [)cduncle. The external ])late of the swimmeret is 

 never transversely divided by a suture. 



The second section, Locust.^!; (so named from the Latin name Lociista. given to the mo^t remark- 

 able species of this section by the Romans), have only four jiairs of false legs. The extrcMuitv of the 

 swimmeret at the end of tlic tail is always nearly membranous, or less solid than the rest. The pe- 

 duncle of the intermediate antenna; is always longer than the two terminal filaments, and moie or less 

 elbowed. The lateral pair have no basal scale, and sometimes they are even widened to a short but 

 greatly-dilated plate; sometimes they are very large, long, and much spined. The legs are all nearly 

 alike, and terminate in a point, — the anterior pair being but slightly larger than the follo\\ ing ; tlicir 

 penultimate joint, as well as that of the two posterior, is at most unidentate, but not so mucli so as to 

 form a perfectly didactUe band. The car;ii)ax has no frontal elongation, like a pointed iieak or lance. 



i^cijUarus, Fahr., exhibits, in its lateral antenna?, a pei'fectly isolated charactei", the terminal filament bein"- 

 obsolete, and the basal joints greatly dilated transversely, forming a broad, flat, horizontal, and more or less 

 toothed crest. The outer branch of the subabiluminal appendages is terminated by a leaflet, but the inner one, in 

 some males only, appears in the form of a btuth. Leach separated them into the genera tSci/Uants, Themis, and 

 Ibacus, founded upon the proportions and furms of the thorax, the position of the eyes, and other parts. Thev 

 form barrov/s in argillaceous ground near the shores, in which they reside. Type, Sri/l/anis arctus, Linn. iS'cy^ 

 larus <.equino.xialhs, Fabr., is another species, the flesh of which is greatly esteemed [in the Mediterranean]. 



Palinuni-s, Fabr., have the lateral antennai large, setaceous, and set with sharp points. These Crustacea, called 

 by the Greeks Carabos, and by the Romans Locusta, are amongst the largest animals of the class. The [common} 



• IM. Milne KdwnrrlH li:.s publishcil n vnlurilile nir)tini,rrriiih ui>on tlic | T^'itiirrllei, \\V\<:\\ h;i3 Wcu a^J^^r,•ll.■I^.■d in vol. ii. of his Hi:,!. \<it. 

 Pnifuritia; In vol. vi. of Uie riL-w s..-r:,s ..f ihe .'J,n<-i/' ■'■ dr.i Scinufs \ drs CTNsf.iUs.] 



