DECAPODA. 71 



The intermediate antennae of others are terminated by long 

 threads^ they constitute our second division to which we refer. 



Fenxus monodon. Fab.; Squilla indica, Bont., Hist. Nat., p, 

 81, which inhabits the Indian Ocean. 



F. antennatus, Risso, Crust., II, 6, and F. mars, Id., II, 5, 

 also appear to belong to it. 



Stenopus, Lat. 



Distinguished from the Pensei by the transverse and annular di- 

 visions of the two penultimate joints of the four posterior feet. 



The entire body is soft; the antennae and feet are long and slender, 

 those of the third pair widest. 



But a single species is known. It was brought from the seas 



of New Holland by M. Peron and Lesueur. Olivier retains it 



in the genus Palsemon — Cancer setiferus, L.; F. hispidus, Oliv., 



Encyclop. and Atl., d'Hist. Nat., CCCXIX, 2; Seba, Mus., Ill, 



« XXI, 6, 7; Herbst., XXXI, 3, where I first placed it. 



The remaining Carides, the intermediate antennse of many of 



which are terminated by three threads, have at most but two pairs 



of didactyle claws formed by the four anterior feet. 



A subgenus founded on a single species peculiar to North Ame- 

 rica, that of 



Atya,, Leach, 



Is removed from all analogous Crustacea by an anomalous cha- 

 racter. The forceps terminating the four claws is cleft down to its 

 base, or seems to be composed of two fingers in the form of thongs 

 united at their origin; the preceding joint is crescent-shaped. The 

 second pair is the largest. The intermediate antennas have but two 

 threads. 



In all the following subgenera, the blades of the forceps originate 

 at a certain distance from the base of the penultimate article, or of 

 that which has the form of a hand; the body or the part that pre- 

 cedes it is not lunulated. 



We now have in the first instance those Carides whose feet are 

 generally robust and not filiform, and which have no appendage to 

 their external base. Their body is neither very soft nor greatly 

 elongated. 



Among these subgenera, whose feet are deprived of this appen- 

 dage, the three following present an insulated form with respect to 

 their claws. 



Crangon, Fab. 

 The two anterior claws, which are larger than the subsequent feet,^ 



