ORDER DECAPODA. 195 



Mysis, Lair., 



Have the antennge and feet exposed, the testa elongated, 

 almost square or cj'lmdrical, the eyes very much approx- 

 imate, and the feet capillary, as it were, formed of two 

 threads. [Mysis Fahricii, Leach.) 



Cryptopus, Latr., 



Plave a subovo'id testa, enlarged or swollen at intervals, folded 

 inferiorlj on the sides, enveloping the body as well as the 

 antennae and feet, and leaving discovered underneath nothing 

 but a longitudinal cleft. The eyes are wide apart. The feet 

 are in the form of lashes, with a lateral appendage. {Crypto- 

 pus Defrancii, Lat.) 



Sometimes the eyes are concealed. The intermediate an- 

 tennae are conical, inarticulate, and very short. The lateral 

 ones are composed of a peduncle and a thread, without dis- 

 tinct articulations. Their base presents no scale, at least 

 projecting. 



MuLCiON, Latr. 



The body is very soft, with the thorax ovoid. The feet are in 

 the form of a lash, and the majority at least have an appen- 

 dage at their basis. The fourth pair is the longest of all. 

 {Mulcion Lesueurii, Latr.) 



Nehalia, which we had at first placed in this section, not 

 having natatory appendages under the last segments of their 

 body, and their feet being pretty similar to those of cyclops, 

 will pass with condylura into the order of branchiopods, of 

 which they will make the beginning. Nehalia, from their very 

 projecting eyes, which appear to be pedicled, and from some 

 other characters, seem, with zoe, to link the schizopoda with 

 the branchiopods. 



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