studios oil inariiio Oslracods 379 



there is variation within the species; like the secondary teeth on the succeeding claws, they are 

 directed obliquely ventrally-distally. On the following three to five claws the medial row of 

 teeth is absent; the lateral row on these is about the same as the corresponding row on the first 

 claw, but the teeth are somewhat weaker the more posteriorly they are situated. These four 

 to six claws are bare or almost bare dorsally; their distal parts are also quite bare. Of the 

 succeeding claws the anteiior ones, like the preceding ones, are furnished with a lateral row 

 of rather coarse teeth; distally they are moderately strongly pectinated dorsally and ventrally 

 right to their points; the coarse secondary teeth become more and more rare on these claws 

 the more posteriorly the claws are situated; on the most posterior they are often quite missing; 

 distally the posterior claws are finely pectinated dorsally and ventrally. On the anterior claws 

 there is often a transverse row of long, stiff, smooth bristles proximally-medially. Similar bristles 

 may also be found on the lamellae medially close to the claws. The pilosity of the lamellae varies. 



Male: — In this sex the furca is of about the same size as in the female, but it is 

 constructed more weakly. The number of claws is the same or only slightly less than in the 

 female; their equipment is somewhat weaker. 



Upper lip: — This shows no sexual dimorphism. — It seems to be subject to only 

 very slight variation within this genus. Because of this I did not think it necessary to reproduce 

 it, but merely refer the reader to G. \V. MUlleu's reproduction, 1908, pi. VI. fig. 15. It is rather 

 small and somewhat helmet-shaped, with an unpaired conical median process, pointing somewhat 

 upward and forward; on the point of this process there is a small glandular field. Between 

 the lip and the frontal organ there are some irregular protuberances. 



The median eye is well developed in both sexes (it is less pigmented in the female 

 than in the male). The rod-shaped organ is also similarly developed in the two 

 sexes; it is long and narrow and grows slightly narrower distallv. 



Lateral eyes: — These are reduced in the female, being only represented by a little 

 claviform unpigmented process on each side, in the distal part of which there are remains of 

 the crystalline cones of a few ommatids. (Sometimes quite disappeared?). In the males, on the 

 other hand, the lateral eyes are very well developed and situated rather far towards the back. 



There are never any gills. 



Special terminology: — First antenna: — The far-reaching agreement that 

 I have stated between the position of the bristles on the original seventh and eighth 

 joints in this genus and the position of the bristles on the corresponding joints in the sub- 

 family Cypridininae can scarcely be explained in any other way except by an assumption that 

 these bristles are really homologous. Because of this I considered that I was justified in using 

 the same alphabetical notation for these bristles in this genus as was used above for the sub- 

 family just mentioned. Of the bristles on the original seventh joint the anterior one is accord- 

 ingly called the a-bristle, the medial one the b-bristle and the two posterior bristles the Ci and c, 

 bristles. Of the bristles on the original eighth joint the two that are situated close to each 

 other laterally are called tlic d- and e-bristles (the anterior one the d-bristle and the posterior 

 one the c-bristle), the anterior-medial one the f-bri.stle and the jjostem-medial one the g-bristle. 



