

CYPR01DEA. 2283 



The maxillge are also very similar in the two genera. The number 

 of plumes ciliating the moveable plate was fourteen in the species 

 of Cythere, studied by the author, the same as found by Dr. Baird.* 



In the following pairs of legs the two groups diverge from one 

 another. Yet still the type in Cy there is indicated in Cypris ; for the 

 legs of Cythere are similar in general structure to the first pair in 

 Cypris. The form is slender, and they end in a long spiniform claw. 

 But in Cypris, the pair corresponding to the first pair in Cythere is a 

 very short maxilliped, having a maxilliform process anteriorly, and a 

 short single-jointed process behind. The last pair in Cypris, instead 

 of being a proper leg, like the preceding pair, as in Cythere, is reflexed 

 so as to pass up into the egg-cavity. 



The three pairs of legs in Cythere are quite similar, and increase in 

 size from the first to the last, as shown in fig. 9 a. They are sup- 

 ported at base by a framework of corneous processes lying on the 

 skin of the side of the body, as shown in figure 9 k, one process being 

 articulated with the base of each leg, and another process on the 

 venter forming the support on that side. 



The abdomen affords the most striking distinction between the 

 groups. In the Cyprinse it has a furcate styliform extremity, each 

 branch having a few setse at and towards apex on the upper side (fig. 

 7 c, Plate 90). In the Cy thermae, it bears two large fleshy lobes, 

 which lie side by side, and have on the margin a single stout spine, or 

 small setigerous joint. Figures 9 a, e,f, g, h, t, Plate 89, represent this 

 structure in the Cythere Americana, D. In figure 9 a, the female abdo- 

 men is seen in place, and in fig. 9 e, the male abdomen. The specimens 

 were put in boiling water, in order that the shell might be easily removed 

 for the study of the animal within ; the process was perfectly success- 

 ful, and in one case, the abdomen was found thrown out of the shell, 

 as shown in figure 9/. These figures represent a side view, and 

 exhibit only the lateral surface of one of the lobes ; c, in these figures, 

 is the proper caudal extremity of the animal, the lobes being below 

 and anterior to this ; s, is the spine on the margin of the lobe, and a, 

 the anterior angle. In the course of the dissections, the abdomen was 

 made to lie open, as in fig. 9 g; here the two lobes are simply opened — 

 the letters s, a, showing the corresponding parts, and their relation to 

 the abdomen in place (fig. 9 e) . In another case, one lobe was pushed 



* Brit-Entomosfc., p. 166. 





