C Y P R I D E A. 



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eyes contain each twenty to twenty-five facets. The flagellum of the 

 second pair of antennae consists of seven short joints. The mandi- 

 bular process is a thin horny prominence, ciliated or pubescent at the 

 margin. The third pair of maxillae consists of two joints, the second 

 is transverse subovate and margined with hairs. The ovarian feet are 

 nearly as in the luteola. They are very flexible and worm-like in 

 their twisting motions. Found, by dissection, an ovary containing 

 eggs ; but there were no external eggs beneath the shell. 

 This is a beautiful species. 



Subfamily HALOCYPRIN^E. 



The two genera in this subfamily have, in most points, a similar 

 structure. 



They differ widely from the preceding in the antennae and man- 

 dibles, and the posterior feet. Moreover the eyes are not compound : 

 these organs were not very distinctly made out, but in one species 

 were believed to be distinguished as two simple eyes near the medial 

 line, just posterior to the base of the tentacles. The fleshy exsertile 

 spiculum between the anterior antennae is also peculiar to the genus. 

 Moreover, the shell has an opening in front, through which the 

 antennae may be exserted without opening the valves of the shell. 



The anterior antennae in the species seen consist of three joints, the 

 third of which is shortest, and bears at apex several long setae, one or 

 more of which are curved. 



The exsertile spiculum is in one genus dart-like at the extremity, 

 and in the other obtuse acicular. It proceeds from between the bases 

 of the antennae, and is exserted at the will of the animal. 



The second pair of antennae resemble those of the Cypridinae. They 

 have a very large basal joint, muscular within, bearing at the extre- 

 mity two branches : one short and one- or two-jointed, the other con- 

 sisting of an oblong basal joint and five (or seven ?) very short joints 

 furnished with long plumose setae. 



The mandibular feet are five-jointed; the first and second are rather 

 long, and at right angles with one another ; the other three are much 

 shorter, with several setae at apex, which are unilaterally setulose; 

 these last are abruptly inflexed in one of the genera (Conchcecia), 

 while the organ is nearly straight in the other (Halocypris) . At the 



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