226 
CRUSTACEA. 
Naupredia, Lat. 
But ten feet, all in one continuous series ; the base of the second 
and two following pairs provided with a vesicular body 
Caprella, Lam. 
Ten feet also, but in an inlerrupted series, commencing with tlie 
second segment, exclusive of the head ; both this segment apd the 
following have two vesicular bodies, and are totally deprived of 
feetf . 
The other — Ovalia, Lat, — Lsemodipoda have an oval body with 
transversal segments. The stem of the antennae appears to be inar- 
ticulated, and the feet are short but slightly elongated; those of the 
second and third segments are imperfect and terminated by a long 
cylindrical joint without a hook ; their base is provided with an 
elongated vesicular body. They form the subgenus. 
CvAMus, Lat . — Larunda, Leach. 
I have seen three species, all of Avhich live on the Cetacea ; 
the most common, Oniscus ceti,L.‘, Pall., Spicil. Zool. Fascic. 
IX, iv, 14 ; Squille cle la Baleine, De Geer, Ins., VII, vi, 6; Pyc- 
nogonum ceti. Fab.; Savig., Mem. sur les anim. sans verteb. 
Fascic., I, V, 1, is also found on the Mackerel : it is called by 
fishermen Pou de Baleine.' A second very analogous species 
was broTight to France by the late Delalande from the Cape of 
Good Hope. The third, Avhich is much smaller, establishes 
itself on the Cetacea of the Indian Ocean. 
ORDER V. 
ISOPODA t 
The Isopoda approach the Laemodipoda by the palpi of the man- 
dibles being absent, but are removed from tliem in several other re- 
* A subgenus founded on a species from the coast of France, which appears to me 
undescribed.. 
•t The Squilla lohata, Miill., Zool. Dan., LVI, 4, 6 ; his Gamtnarus quadrilobafus, 
Ib., CXIV, 12; the Oniscus scolopendroides, Pall, Spic. Zool. Fascic., IX, iv, 15, are 
Caprellae, but their specific differences are not well characterized. We had referred 
the Cancer linearis, L., to the first, which, now appears doubtful. His Cancer 
filiformis is probably a Caprella ; the Cancer phetsma, Montag., Trans. Lin. 
Soc., VII, vi, 2, is a congener. His figure is copied Encyc. Method., Atl. d’Hist. 
Nat. CCCXXXVI, 37. For details concerning this order and genus, see the Nouv. 
Diet. d’Hist. Nat., Ed. II, and the work of Desraarest on the Crustacea. 
X The Polygonata, Fab., with the e.xception of the genus Monoculus. 
Messrs. Audouin and Edwards — Ann. des Sc. Nat., Alrout 1827, p. 379, 381 — 
huve published some interesting observations on the circulation of the Isopoda, and 
