60 MEMOIR III. 



Corselet, somewhat taper, truncate or sliglitly cmargiiiate 

 anteriorly. 



Abdominal portion taper, of six segments, the last 

 long and very slender. 



Tail of five scales ; the outer ones broad at the base, 

 acuminate and ciliated ; intermediate scales taper and 

 ciliate ; middle scale very short and pointed. 



Eyes very large, on extremely long, slender, divaricate 

 footstalks. 



Antennce; near to the insertion of the footstalks of the 

 Eyes, are two short appendages which are probably the 

 rudiments of the upper antenna ; the lower pair of antennae 

 are as long as the corselet, filiform, composed of four joints 

 tipt with hair. Scales equal in length to the antennae, taper 

 and ciliated on their inner edge. 



Thoracic members ; one pair unique, nearly twice the 

 length of the corselet, of five joints, the last hairy within ; 

 the rest of the members appear to be composed of three or 

 four ? jpints, and hirsute. 



Sub-ahdotninal Jins, five pair, each, of two or three joints, 

 the terminal joints ciliated, and doubled in the two last pair. 



General Remarks on the Shizopodce. 



Having completed the description of all the cleft-footed 

 Crustacea decidedly belonging to this Order, as well as of 

 such as from their structure arc presumed to be referable 

 to it, and which if they do not find place here, cannot be 

 associated with any other known group, it may be advan- 

 tageous to review the characters which are peculiar to these 

 animals, and which appear to distinguish them from the 

 Decapodous Macroura, (Shrimps, &c.) which they most 

 resemble. In all the well defined genera of the Shizopodae 

 viz. Mysis, Nocticula, and Cynthia, we have found a 

 greater number of locomotive members or feet viz. eight 

 pair, divided to the Coxae (hip) into two branches, of which 



