CRUSTACEA. 
418 
The best known species (Cawcer Linn.) inhabits the Isle of France; and, according to a native tradition, ^ 
it feeds upon the fruit of the cocoa-nut, making its excursions during the night. [It is of large size, and is called j 
the Purse Crab. Mr. Cuming found it in abundance in Lord Hood’s Island in the Pacific, living at the roots of ; 
trees. Messrs. Quoy and Gaimard fed this species for many months on cocoa-nuts ; and Mr. Cuming discovered ^ 
that it climbs the Platamis odoratissima, to feed upon the small nuts of that tree.] 1 
In the Hermit Crabs {Pagnrus, Fabr.), the four hind-legs are much smaller than the preceding, with the claws .1 
covered with small tubercles. The tail is soft, long, cylindrical, narrowed at the tip, and only furnished with one 1 
row of filiform, oviferous appendages. The thorax is ovoid or oblong, i 
With the exception of some superficially-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 claws, which is ’ 
larger 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. Crawling 
slowly along the line of empty shells, &c., left by the last wave, and unwilling to part with their now incom- I 
modious domicile until another is obtained, they carefully examine, one by one, the shells which lie in their way, n 
slipping their tails out of the old house into the new one, and again betaking themselves to the old one, if this | 
should not suit. In this manner they proceed until they have found a habitation to their liking. They feed upon | 
dead fish, and all kinds of garbage thrown on the shore ; and, when 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 breaking the shell to pieces.] S 
Some species, forming the subgenus Ccenobita, Latr., are distinguished by the antennae 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, Pagurus, have the inter- ^ 
mediate antennae short and bent, with two short filaments. The front division of the thorax is square, or reversed ^ 
triangular. ■ 
Cancer Bernhardus, Linn. (Pagurus strehlonyx, Leach), is very common on the coasts 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. Pag. Faugasii, Desmarest, a fossil species, approaches it very closely. 
Another species from the Mediterranean differs from the rest in many characters, and forms the subgenus 
Prophylax, 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 serpulae, alcyons, &c., such as Pagurus tubularis, Fabr., belong : 
to this subgenus.* 
In all the subsequent Macroura. the two posterior legs alone are smaller than the preceding. The 
subabdominal appendages are generally five pairs. The teguments are crustaceous. The lateral appen- 
dages of the penultimate segments form a fan-like swimmeret in conjunction with the terminal one. 
The two following sections have a character in common, w^hich separates them from the fourth, or 
that of the Carides. The antennae are inserted [in a line] at the same height, the peduncle of the 
lateral pair being never entirely covered by the scale when present. Often there are only four pairs of 
the false suhahdominal feet. The intermediate antennae are never terminated by two threads ; they 
are ordinarily shorter, or scarcely as long as their peduncle. The external plate of the swimmeret is 
never transversely divided by a suture. 
The second section, Locusts (so named from the Latin name Locusta, given to the most remark- 
able species of this section by the Romans), have only four pairs of false legs. The extremity of the 
swimmeret at the end of the tail is always nearly membranous, or less solid than the rest. The pe- 
duncle of the intermediate antennae is alw^ays longer than the two terminal filaments, and more 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 following ; their 
penultimate joint, as w'ell as that of the two posterior, is at most unidentate, but not so much so as to 
form a perfectly didactyle hand. The carapax has no frontal elongation, like a pointed beak or lance, m 
Scyllarus, Fabr., exhibits, in its lateral antennae, a perfectly isolated character, 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 subabdominal appendages is terminated by a leaflet, but the inner one, ini 
some males only, appears in the form of a tooth. Leach separated them into the genera Scyllarus, Thenus, andj 
Ibacus, founded upon the proportions and forms of the thorax, the position of the eyes, and other parts. They^ 
form burrov^s in argillaceous ground near the shores, in which they reside. Type, Scyllarus arctus, Linn. Scyl-^ 
larus vequinoxialis, Fabr., is another species, the flesh of which is greatly esteemed [in the Mediterranean]. 
Palinurtis, Fabr., have the lateral antennae 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 [commo n]^ 
* [M. Milne Kdwards has published a valuable monograph upon the 
Pagurid® in vol. vi. of the new series of the Annnles des Sciences 
Naturelles, which has been abstracted in vol. ii. of his Hist. Natx 
des Crust aces. 
