studies on marine Oslracods 663 



and about as wide as the f-bristle proximally, bare or with extremely short and fine hairs. The 

 h-bristle has a spinous shaft, the f-, g-, i- and j-bristles have no shafts. 



Mandible: — Protopodite: Coxale: The toothed edge of the pars incisiva 

 has about ten teeth. The distal tooth-list is of about the same relative size and tvpe as has 

 been previously described for C. oblonga, but the number of teeth is on the average somewhat 

 fewer. The proximal tooth-Hst also varies within about the same limits as the corresponding 

 part in the species just mentioned, but here, too, the number of teeth is on the average somewhat 

 less. The masticatory pad is very powerfully developed; it is divided into from four to six more 

 or less distinct transverse ridges; the distal one of these is about as wide as the two tooth- 

 lists, the next distal one is about half as wide, the others decrease somewhat in width the more 

 proximally they are situated. The whole masticatory pad is armed with rather small papillae, 

 placed close together. The part of the pars incisiva that is surrounded by the lancet bristles 

 and hairs is rather powerful and is armed vvith papillae similar to those on the masticatory 

 pad; this part is also armed with a couple of low and powerful teeth. Basale: The six teeth on 

 the distal edge of the endite are furnished with moderately fine serrulation. The single tooth 

 on the outside of this endite is more powerful than in my fig. 19 of C. symmetrica and is of the 

 same type as has been described for C. elecjmis. The epipodial verruca is very small 

 and has a very short bristle. The e x o p o d i t e verruca is very weakly developed. 

 Endopodite: The first joint has only two posterior bristles, both with short hairs; these 

 have about the same position and relative length as the two corresponding bristles in C. 

 rotundata. Pilosity: The second endopodite joint has hairs. 



Maxilla: — Protopodite: Endite on the procoxale: Besides the anterior 

 inner tube-bristle the two bristles nearest to this are also provided in most cases with long 

 secondary bristles. The basale has no bristle. Endopodite: First joint: The six bristles 

 on the anterior side of this joint are somewhat relatively shorter than in most other species of 

 this genus. The end joint is of about the same type as in C. rotundata. 



Fifth limb: — Protopodite: The longer of the two tube-bristles on the 

 second endite has short hairs. Endopodite: This is similar to that of C. oblonga. 

 Exopodite: The first joint is similar to that of the above-mentioned species, but all the 

 ventral bristles usually have short hairs. The ventral end claw varies in length; sometimes 

 it is only a quarter or a sixth of the length of the middle claw. 



Sixth limb: — Exopodite: The ventral bristles on the first joint are some- 

 times somewhat relatively shorter than in my fig. 29 of C. symmetrica; the dorso-lateral and 

 dorso-distal bristles sometimes seem to be quite absent. 



Penis: — This is of the type reproduced by G. \\. MCLLER, 1906 a, pi. XXX, fig. 9; 

 it has a rather narrow copulatory appendage; cf. the accompanying fig. 5. 



Furca: — There is no unpaired bristle behind the claws. 



Rod-shaped organ: — The shaft reaches to about the distal boundary of 

 the second joint of the first antenna or somewhat farther. The capitulum is of about the type 

 described and reproduced by G. \X. Mi'LLHK or else it is somewhat more curved in anteriorly; 

 cf, the accorapanying fig. 6; it is sometimes somewhat more pointed distally than in 



