DECAPODA. 
193 
It appears that from their size, the form of their tail, and the 
more solid consistence of their teguments, the Birgi are unable to 
shelter themselves in shells. They must retreat to holes, or fissures 
in the rocks. 
The best known species. Cancer latro, L., Herbst. XXIV ; 
Rumph., Mus., IV ; Seba, Thes., Ill, xxi, 1, ‘2, according to the 
Indians, feeds on cocoa-nuts, which it obtains during its nocturnal 
excursions for that purpose *. In the others, or the 
Pagurus, Fah., 
The last four feet are much shorter than the preceding ones, and 
the forceps are covered with granules. The tail is soft, long, cylin- 
drical, narrowed near the extremity, and has usually but a single row 
of filiform oviperous appendages. The thorax is ovoid or oblong. 
With the exception of some species domiciliated in sponges, Ser- 
pulas and Alcyonii, they all inhabit univalve shells, Avhose aperture 
they close with their anterior claAVs, and most frequently Avith one of 
their fingers, Avhich is usually larger than the other. It is asserted 
that the female spaAvns tAvice or thrice in the year. 
Some species, C.enobita, Latr. ; distinguished from the others by 
their projecting antennae, of Avhich the mediate are nearly as long as 
the external or lateral, and are furnished AA'ith elongated filaments, 
Avhose thorax is ovoido-conical, narroAV, elongated, strongly com- 
pressed on the side, Avith the anterior cephalic portion shaped like 
a heart, establish their domicile in terrestrial shells on rocks near 
the sea, Avhence at the approach of danger, they roll doAvn Avith 
them f . 
The true Paguri — Pagurus, Latr., — on the contrary, have the me- 
diate antennae curved, much shorter than the lateral ones, with the 
tAVO filaments short, the superior forming an elongated or subulated 
cone ; the anterior division of the thorax is square, or forms a reversed 
and curvilinear triangle. They inhabit marine shells. 
The Hermit , — Cancer Bern/iardus, L., Herbst., XXII, G; Pa- 
gurus strehloni/x, Leach, Malac. Brit., XXVI, 1 — 4, — is of a 
mean size. Its tAvo claAvs are bristled Avitli spines, Avith the 
forceps almost in the shape of a lieart, the right one being the 
largest. The last joints of the ensuing feet are also sifinous. It 
is very common in European seas. A second but fossil species, 
the Pagure de Faujas, — Desmar., Hist. Nat. des Crust. Foss., 
XI, 2, — is closely allied to it. 
A third species, the Pagurus angulatus, Risso, Crust, de Nice, 
I, 8; Desmar., Consider., XXX, 1, is remarkable for its forceps. 
* Pagurus luHcauda, Cuv. Auim., IV, xii, 2; Desmar., Consider, j). 
180, from the Isle of France. Very curious facts relating to the anatomy of the 
preceding species have been published by M. Geoffroy Saint-Hilaire, from which 
however we do not draw similar conclusions, 
t Pagurus clypealus, Fab.; Herbst., xii, 2. 
VOL. Ilf. 
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