studies on luariiu! Oslracods •J'lS 



as long as this limb. E-bristle: Somewhat distally of the middle this bristle has, along about 

 a quarter of its length, two rows of moderately strong spines pointing proximally, about fifteen 

 to twenty in each row. All the spines are pointed and rather narrow, moderately long, the distal 

 ones are somewhat shorter than the proximal ones; cf. the accompanying fig. 5. The distal 

 spines in the two rows are arranged in pairs, but even at the fourth or sixth spine, counting 

 distally-proximally, a tendency to alternation can be observed- from about the ninth or tenth 

 spine all the spines are situated alternately. The two rows are well separated distally and 

 approach each other more and more proximally until they form almost a single row. Distally 

 of these rows of spines this bristle is quite bare, i. e. it has no more or less distally pointing spines 

 such as we find, for instance, in my fig. 15 of C. elegans; cf. V. VAvRA, 1906, pi. I, fig. 17. 

 Just distally of these rows of spines this bristle is bent into a distinct angle; the part distally 

 of this knee is not sword-shaped, but narrow. On the part proximally of the rows of spines 

 there are on the anterior side of this bristle sparse short secondary bristles. The b- and d-bristles 

 are not or are only slightly bent at an. angle and are not widened distally. The b-bristle 

 is furnished with a shght pad about opposite the spines of the e-bristle; distally of this pad 

 there are in most cases some short, distally pointing, fine secondary bristles. The d-bristle 

 has no pad but is furnished at about the corresponding place with secondary bristles that are 

 about similar to those on the b-bristle. The a- and c-bristles are most frequently subequai 

 or else the former is rather slightly longer than the latter; they are about as long as or somewhat 

 shorter than the second joint. Neither of them has accessory saccules. The c-bristle is in most 

 cases straight, the a-bristle more or less bent, but not rolled up like a spiral; cf. the accompanying 

 fig. 6. All the joints are quite bare. 



Second antenna: — Protopodite: In specimens with shells about 1,2 mm. 



long this was about 0,5 mm. long. The distal medial verruca is in most cases irregularly lobate 



in shape. Exopodite: The proportion between the length of this branch and the length 



of the protopodite is about 10 : 16 or 10 : 17. The proportion between the length of the first 



joint and the total length of the eight following joints is about 8 : 3 or 9 : 4. The proportion 



between the length of the longest natatory bristles and the length of this branch is about 5 : 3 



or 4 : 3. As far as I could discover with Reichert's ocular 4, Leitz's immersion Via, the fii'st 



joint is quite bare. Endopodite (see the accompanying figs. 9 and 10): First joint: The 



processus mammillaris is comparatively small and has no distal verruca. The a-bristle is 



fui-nished with short, fine hairs. The b-bristle, which also has short, fine hairs along the greater 



part of its length, has some (from about five to twelve) moderately long, stiff secondary bristles 



proximally of the middle. Second joint: The c- and d-bristles are of somewhat different lengths; 



the longest is not quite as long as this joint; they both have short, fine hairs or are almost bare. 



The e-bristle is exceedingly short. The g- and f-bristles are comparatively short and narrow; 



the proportion between the length of the g-bristle and that of the protopodite is about 4 : 5 



or 3,5 : 5. The f-bristle is about a fifth or a quarter shorter than the g-bristle. The g-bristle 



has short, fine hairs, the f-bristle is bare. On the right antenna these two bristles are fui-nished 



with shafts of the type described by G. W. MOller, 1901; on the left antenna there are only 



traces of a structure of this sort. Third joint: The clasping organs are of the types described 



