242 CRUSTACEA. 



is parasitical, and, as I think I perceive in it a vestige of a sucker, I 

 have placed it among the Poecilopoda. I Avould observe, however, 

 that the feet, the anterior excepted, closely re's'emble those of Cyclops, 

 and that the females also carry their ova in two sacs situated at the 

 base of the tail as in the latter genus *. 



In the remaining Lophyrojja of our first division, the thorax, as 

 in the Condylura, is divided into several segments, the first of which 

 is mixch the largest ; they have but one eye situated in the centre of 

 the front between the superior antennse. such is the 



Cyclops, Miill., 



So well studied by Jurine, Sen., and Randohr. The body is more 

 or less oval, soft or gelatinous, and divided into two portions, one 

 anterior, composed of the head and thorax, the other posterior, or 

 the tail. The segment immediately preceding the sexual organs, and 

 which, in the female, is provided with two appendages in the form 

 of little feet— /w/cra, Jurine — maybe considered as the first of the 

 tail, which is not always decidedly or suddenly distinguished from 

 the thorax. It is composed of six parts or segments ; under the 

 second in the males, are two articulated appendages, sometimes sim- 

 ple, and at others with a small branch on the inner side of various 

 forms, and constituting, cither wholly or partially, the organs of 

 generation. The vulva, in the other sex, is situated on the same 

 segment. The last one is terminated by two points or stylets, form- 

 ing a fork, and is more or less furnished with setae or peniform threads. 

 The other or anterior portion of the body is divided into four seg- 

 ments, the first of which is much the largest, and composes the head 

 and part of the thorax, which are also covered by a common scale. 

 In it, are inserted the eye, four antennae, two mandibles — mandibules 

 internes of Jurine, furnished with a palpus, either simple or divided 

 into two articulated branches, two jaws — mandibules externes, or 

 levre avec des barbillons of Jurine f, and four feet, each divided 

 into four cylindrical stems furnished with hairs or bearded threads ; 



* Near the Condylurae should be placed the genus Cuma, M. Edwards, Ann. 

 des Sc. Nat. XIII, xiii, B. The superior antennse are rudimental, and consist of 

 but one joint. The head is distinct from the thorax, which is divided into four seg- 

 ments, to the first of which are attached the four anterior feet, each of the follow- 

 ing having a pair ; all these feet are natatory, directed forwards, and have no hook 

 at the end ; the two first pairs alone are bifid. 



The genus Pontia, Id., lb., XIV. appears to us to approach Cyclops. The 

 head is distinct from the trunk, and terminated by a rostrum which is rather acute 

 and appears to be formed of two pieces; it has two sessile eyes; four antennae, the 

 superior of which are setaceous, multi-articulated and ciliated ; the inferior are 

 pediform, composed of a peduncle, serving as a base to two divisions or branches, 

 each terminated by a pencil of hairs, one of them having two joints, the last widened 

 at the end, and the other consisting of one. The thorax is divided into five annuli, 

 and has six pairs of natatory and bifid feet. The abdomen is formed of two segments 

 and terminated by two spatula-like appendages or fins. 



f According to the successive order of the parts of the mouth in the Decapoda, 

 the part situated immediately beneath the mandibles is the ligula ; but the denta- 

 tion of those here spoken of indicates maxillary organs, Ihc ligula may have 

 escaped the notice uf M. Jurine. 



