studies oil niiiiiuu Oslracods 671 



dorso-lateral bristle is furnished with long hairs. The bristles on this joint are of about the same 

 relative length as in my fig. 27 of C symmetrica. The dorsal bristle of the end joint is relatively 

 somewhat shorter than in the figure just mentioned. 



Sixth limb: — E x o p o d i t e: The bristles of the first joint are in most cases 

 about the same as in my fig. 29 of (J. symmetrica (the number of the ventral bristles is sometimes 

 somewhat reduced?). The ventral bristle of the third joint is relatively long, often about as 

 long as the height of this joint. 



The end joint of the seventh limb is provided with spines. 



Penis: — This has almost the same height along its whole length and is obliquely 

 rounded distaUy. There are six rather broad oblique transverse muscles at the middle, distally 

 of which there are no muscles. It has a well developed and moderately wide copulatory appen- 

 dage of about the type reproduced in fig. 6. 



F u r c a : — There is no unpaired bristle behind the claws. 



Rod-shaped organ: — This is of the type described and reproduced by 

 G. W. MULLER; cf. the accompanying fig. 3. 



Upper 1 i J): — The part between the combs on the postero-ventral edge of this lip 

 is usually somewhat, though only rather slightly, more deeply notched in the middle than it 

 is in my fig. 37 of C. symmetrica. 



Female: — 



Shell: — Length: According to G. S. BliADY and A. M. NORMAX, 3 mm.; 

 G. W. MULLER, 1906 a, gives 2,2—2,95 mm. (cf. p. 668 above); G. H. FowLER, 2,5—3 mm. The 

 specimens measured by me were 2,7 — 3,2 mm. long. Seen from the side it is of about 

 the type reproduced by G. W. MtJLLER. Seen from below it is of about the same type 

 as in the male, but the posterior part of the shell is somewhat larger than in the latter and the 

 anterior part somewhat smaller, in other words the anterior part of the shell dominates over 

 the posterior part considerably less than in the male, sometimes the dominance is scarcely 

 perceptible. In other respects it is like that of the male. 



First antenna: — This is of the type reproduced by G. W. MOller. The e-bristle 

 has short hairs on the anterior side of its proximal third. The second joint has a moderate 

 number of short, fine spines scattered proximally ventrally; the fourth joint, too, is armed with 

 similar spines. Exceedingly fine spines of the same kind can also, at least in some cases, be 

 observed at other places on this limb. I did not succeed in finding any yellow pigment cor- 

 puscles in this limb. 



Second antenna: — P r o t o ]) o d i t e: In specimens with shells aboiit 3 mm. 

 long this measured about 1,2 mm. The exopodite is like that of the male. E n d o- 

 p o d i t e: This has two joints: First joint: The processus mammillaris is like that of the male. 

 Second joint: One of the c- and d-bristles is always developed; it has short hairs and is about 

 as long as in pi. XVIII, fig. 8, G. W. MiiLLER, 1906 a; sometimes both of these bristles are deve- 

 loped, in which case one of them is always very short. The g-bristle is of about the same type 

 and length as in the male (i. e. about as long as or somewhat longer than the protopodite). 

 The f-bristle is about a third or a quarter shorter. The h-, i- and j-bristles are subequal, about 



