414 CRUSTACEA. 



The tliird i^oction, Qxjadhtlatera, liiive the carapax nearly square, or lieart-shaped, witli the front 

 generally elongated and dellexed, forming a l<ind of hood. The tail is composed of seTCu segments in 

 both sexes, the joints being distinct tliroughout tlie entire Itreadth of the tail. Tiie antennae are 

 genorallv very sliort. The eyes are generally placed npon long p(;diineles. Many species r<->ide in the 

 groinid, forming buiTows for their retreats, and some frequent fresh water. Tiicy are aide to 

 run very fast. Some of these species have the carapax somewhat lieart-shaped [thus nearly resembhng 

 some of tlte Arciiala]^ with tlie front margin strongly toothed, including the genera Eriphia, Lat., 

 Trapezia, Lat., and Pilumiutfi, Leacli, in which last the claws are of unequal size. 



The TJidphusiC, Lut., have the lateral antennfe shorter than the ocular peduncles, and few-jointed. The carapax 

 i.s nearly of a cordate truncate form, [but broader behind than in the precechnic]. There are several species of this 

 genus, which reside in fresh water, but being able to exist for a considerable time out of their native element ; 

 one noticed by the ancients occurs in the south of Europe; it is the Cancer fliiviaCdis^ Belon. It is often repre- 

 serited upon the ancient Greek medals. The Greek monks eat it uncooked, and it forms a common article of food 

 in Italy during Lent. Delalande and De Latour discovered two other species, one in the south of Africa and the 

 other in the mountains of Ceylon. [I have described and lif!;uj'ed another species, under the name of The/phi/sa 

 nin/cidarU, discovered by Col. Sykes, in the fjhauts of the Ueccan, where it occurs in great abundance, and of 

 which Bishop Heber thus speaks in his Journal :— " All the grass through the Deccan generally swarms with a 

 MiKiU land-crab, which burrows in the p;roui](l, and runs with considerable swiftness, even when encumbered with 

 n lumdle of food as biir as itself; this food is grass, or the green stalks of rice, and it is amusing to see the crab 

 silting, as it were, ujirigtit to cut their hay with their sharp pincers, andthcn waddling off with their sheaf to their 

 iiules, as quickly as their sidedung pace Avill carry them." Col. Sykes found them on the table lands at an eleva- 

 tion of nearly 4000 feet above the sea, and as they are met with of all sizes, he believes that there productive pro- 

 cess is completed without the Crab having to undertake any annual journey to the sea, their migrations having 

 never been noticed.— Tz-a^i^. Enf. .^'oc., vol. i.] To this section also belong other species of Land Crabs, composing 

 the genera Ge/asimuSf Ocypoda, and Micljiri.i. The first of these geuera has the carapax solid, and neaijy quadri- 

 lateral, but rather broader in front ; one of the claws is generally much longer than the other, the fingers of the 

 smaller claws being spoon-shaped. The animal closes the mouth of its burrow, which it makes near the shore, 

 with its largerclaw. These burrows ai-e cylindrical, oblique, and very deeji, each having a single inhabitant. It is 

 the habit of this Crab to hold up the large claw in the front of the body, as though beckoning to some one, 

 whence they have ol^tained the name ot Calling Crabs. The species of Oc_//poda has the eyes extended along the 

 greater length of the foot-stalks. Tlieir claws are also unequal, but not to the same extent as in the Gela-vimi. 

 J)uring the day they sit in their burrows, venturing forth only after sun-set. Tlie type Cancer cursor, Linn., inha- 

 bits Syria and Northern Africa. Other species of Land Crabs are of a truncate cordate form, with the shell rounded 

 and dilated at the sides. They inhabit tropical chmates, and are called by the inhabitants tourlouroux, painted 

 Crabs, land Cral)s, violet Crabs, &;c., which names seem to be applied indiscriminately. There are few travellers 

 wli'i have nui niciitioned their habits, often mixing up much fiction in their accounts. They pass the greater part 

 of tlieir lives in the earth, hiding themselves by day and coming abroad only at night. Sometimes they frequent 

 rciiieteries. Once a year, as the period for depositing tlieir eggs draws near, they assemble in numerous com- 

 panies, and following the most direct line, seek the coa.st without permitting any obstacle to intercept them in 

 their way; after laying then' eggs [in the water] they return, greatly enfeebled. It is said that they close the 

 mouth of their burrows at the period of moulting, after which operation, and whilst still soft, they are reckoned 

 a great delicacy. These species compose the gcTiera Vcu, Latreille, (type Cancer lu-a, Linn., South .Vmerica), ami 

 CcrnrchiHSj Leach, (Cancer ruricola, Cuv., &:c.) 



Another interesting group constitutes the genus Phiuof/n-rcs, Latr. Tbese ar>-' nf very small size [of ^vhieli 

 there are several native species, named pea-crabs], and \s hicb ?-psi(li-, dni-ing a ])oi-M(in of the year at least, inside 

 vai'ious bivalve shells, such as muscles, &c. The caraiiax of the females is suborbieular, very thin and soft ; 

 whilst that of the niales is lirmer and neai'ly glnlndar. and rather pointed in front ; the legs are of moderate 



Ihc tad iif the female is very ample, and covers the whole of the 

 ■d Hint ilir I'ra-rrab !i\cd iipmi tlie br-t imns with the inhabitant of 

 iry imt only wiirned tlirin of dauL-'er, hut wi'iit abroad to cater for 

 . and Lrach has investigated the species in his ilalacostraca Podo- 

 rii (lie males and young as distinct species. See fm-ther J. V. Thomp- 

 son's .Mt.Tiioir oil this genus in the I'Jitnmol. Mag., \<)\. iii.] 

 The section consists of severni other well-marked genera, such as Graj's'i/.\\ Lamarck, Vln<;uf^ia, Latr., &c. 



The fourth section, Ordiculata, have the carapax cither somewdiat globular, or rhomhoidal, or ovoid, 

 and always very sohd ; the ocular peduncles are ahvays short, or but slightly elongated ; the claws of 

 unequal size, accm-ding to the sexes, thof^e of the males being the largest; the tail never consists of 

 seven entire segments; the oral cavity is gradually narrowed towards its superior extrcndty; and the 

 Ihii'd joint of the outer foot-j;iws is always in the Inriti of a Igng triangle ; the posterior legs re^emhle 

 tlic pi'cccding, and none t;if tlu'm are vcrv long. 



Conjates, Latr., has the carnpax of an ovuithoblong form, with the lateral antenn;e [nearly as long at: the body], 



