186 
CRUSTACEA. 
tremely spinous, and terminated anteriorly by a dentated point. These 
Crustacea are peculiar to the Arctic Seas *. 
Our sixth section, that of the Cryrtopoda f. consists of Brachyiira 
remarkable for a vaulted projection of the posterior extremities of their 
shell, under which their feet, the two anterior or the claws excepted, 
can be completely retracted and concealed. The shell is nearly semi- 
circular or triangular. The superior edge of the forceps is more or 
less elevated and notched in the manner of a crest. In those species 
Avhere they are largest, they cover the anterior part of their body, 
and hence the name of Coq de mer (Sea Cock), and Crabe Iionteux 
(Bashful Crab), which have been given to some of them. One sub- 
genus of this section, that of j¥Ahra being closely allied by other cha- 
racters with the Parthenopes of Fabricius, the hrst sub-genus of the 
preceding section, it follows, in a natural order, the Cryptopoda should 
be placed between the Orbiculata and the Trigona. 
Calappa, Fabr. 
An extremely convex shell ; the forceps triangular, strongly com- 
pressed, dentated superiorly like a crest, and perpendicularly cover- 
ing the anterior part of the body, during the contraction of the feet. 
The third joint of the external foot jaAA's is terminated like a hook, 
and the superior extremity of the buccal cavity is contracted and 
divided longitudinally into tAVO cells by a septum. 
In most of them, the tAVo ])osterior and lateral dilatations of the 
shell are incised and dentated. 
One s])ecies, the Calappe miqrane, — Cancer granulatus, L. ; 
Calappa (jranulafa. Fab.; Herbst., XllI, 75, 76, vidgarly styled 
Cuq de mer and Crabe honteux, is found in the Mediterranean. 
The shell is reddish and marked Avith tAvo deep sulci, and un- 
equal tubercles of a carmine red. That portion of the lateral 
margin Avhicli precedes the jiosterior dilatations, is at first nearly 
entire, and terminates by four A'ery short teeth, the tAVO first 
being most strongly marked ; those of the edges of the dilatations 
are large, and six in number, tAVo on the posterior margin, and 
the others lateral. There are tAvo others on the front. The 
forceps are also furnished Avith red tubercles, and their crest is 
formed by seven teeth, the superior of Avhich are acute J. 
* Cunctr muja, L. ; Parthenope nicija, Fab. ; IiiacJins niaju, Id. ; Litiwdes arc- 
Hca, Lead), Malac. Itrit., ,x.\iv. See also the Muja caiiijdschensis, Tiles., Mem. 
Acad. St. Pctei'sb. 1812, Y, YI. 
■f' Several of the Arcuata, such as the Ileiaiti, Mursiic, Matutie, among the 
swimmers, have a crested forceps, and seem to he naturally allied to the Crypto- 
poda, .so that this section should be placed higher in the scale. The same observa- 
tion applies to the last one, or that of the Notopoda, for some of them approach the 
Arcuata, and others the Orbiculata and the Trigona. 
+ In th.is division come the following , species of F.'ibricius : C. tubercuJata, 
llerhst., XIII, 78; Iviii, 1 ? — C. loplws, Ilerbst., XIII, 77; — C. cristatus, Herbst.; 
xl, 3; — C. vutniivrufus, Herbst., xl, 2. — The (huija apara, Pison and Marcgr., 
should probably be referred to this species, and, according to the citation of Bart'^re, 
is the Crabe des puUtuciers of the colonists of Cayenne. The Cancer hepidicus of 
Liuiiteus is also a Calappa. 
