98 CRUSTACEA. 



Lin. Soc, II, 6; Encyclop. Method., Atl. d'Hist. Nat. CCCXXXVI, 

 38 those appendages are only proper to the second, and four fol- 

 lowing feet(l). 



Naupredia, Lat. 



But ten feet, all in one continuous series; the base of the second 

 and two following pairs provided with a vesicular body(2). 



Caprella, Lam. 



Ten feet also, but in an interrupted series, commencing with the 

 second segment, exclusive of the head; both this segment and the 

 following have two vesicular bodies, and are totally deprived of 

 feet(3). 



The other Ovalia, Lat. Lsemodipoda have an oval body with 

 transversal segments. The stem of the antennae appears to be in- 

 articulated, 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 



Cyamus, Lat. Larunda, Leach. 



I have seen three species, all of which live on the Cetacea; 

 the most common, Oniscus ceti, L.; Pall., Spicil. Zool. Fascic. 

 IX, iv, 14; Squille de 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 brought to France by the late Delalande from the Cape of 

 Good Hope. The third, which is much smaller, establishes 

 itself on the Cetacea of the Indian Ocean. 



(1) We should also refer to the Leptomerae the Squilla ventricosa, Mull., Zool. 

 Dan., LVI, 1 3; Herbst, XXXVI, ii: the Cancer linearis, L., is perhaps a con- 

 gener. He describes it as having 1 six feet, but does not include the head. 



(2) A subgenus founded on a species from the coast of France, which appears 

 to me undescribed. 



(3) The Squilla lobata, Mull., Zool. Dan., LVI, 4, 6; his Gammarus quadrilo- 

 batus, lb., CXIV, 12; the Oniscus scolopendroides, Pall, Spic. Zool. Fascic, IX, iv, 

 15, are Caprellx, but their specific differences are not well characterized. We 

 had referred the Cancer linearis, L., to the first, which, (see note one) now ap- 

 pears doubtful. His Cancer filiformis is probably a Caprella; the Cancer phasma, 

 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, seethe Nouv. Diet. d'Hist. Nat., Ed. II, and the work of Desmarest on 

 the Crustacea 



