studies on marine Ostracods oOl 



somewhat narrower than that of the female. The medial bristles are similar to those of the 

 female; those on the anterior part of the shell are, perhaps, however, somewhat fewer and 

 longer than those of the female. 



First antenna (fig. 7): — Tliis has seven joints. The proportion between the 

 joints is about as follows: 



li; 11^:; III';; lY ^; V {; VI ] ; VII ^. 



Of the five anterior bristles on the third joint nos. 2 and 5 especially are very 

 nmch shortened. Of these bristles no. 1 has rather numerous long, stiff secondary bristles 

 ventrally, no. 3 is armed with a few similar bristles, bristle no. 2 has moderately long, fine 

 secondary bristles, the others have short hairs. The longer of the two posterior distal bristles 

 on the fourth joint is abo^it as long as the total length of the three following joints. The sensorial 

 bristle of the fifth joint is of quite the same tj'pe as in the female, i. e. it has only six sensorial 

 filaments; its stem is about as long as the posterior side of the second joint. The a-claw is finely 

 pectinated, as in the female. The b-bristle is about as long as the anterior side of the second 

 and third joints and, like that of the female, it has five sensorial filaments. The c- and f-bristles 

 are subequal, about a third longer than the shell (their length was 2,3 — 2,4: mm.). In one 

 specimen twenty sensorial filaments were observed on the c-bristle of each antenna, eighteen 

 on the f-bristle (both these bristles were defective in the other specimen). The g-bristle is 

 somewhat longer than the whole antenna; it has eight sensorial filaments. 



Second antenna: — The exopodite is comparatively slightly lengthened. 

 The relation between the joints is shown by the following numbers: 



cJ (length of shell, 1,6 mm.) = I : II : (III —IX) = 40 : 11 : 22. 



For the sake of comparison I give here the corresponding figures for the female, expressed 

 on the same scale: 



? (length of shell, 1,7 mm.) -- I : TI : (III — IX) -- 31 : 6 : 21. 



The second joint is about as long as the following two or three joints together; the third 

 to the ninth joints are of about the same length, as is the case in the female. All the joints, 

 thus even the end joint, are without basal spines. Endopodite (fig. 9): The three bristles 

 on the second joint are well pointed and decrease uniformly in length; the longest is about as 

 long as the width of this joint at the place where the bristle is fixed, the shortest one is about 

 half as long as the longest one or somewhat more. The third joint is rather broad proximally, 

 lancet-like, with rather broad, thin side borders. Its point has six or seven powerful, chitinized 

 cross-ridges on the inside. Its proximal bristle is somewhat shorter than the joint. 



Mandible: — Protopodite: Basale: The backward pointing process is as 

 strongly developed as in the female; it has no perceptible reduction of the bristles. At 

 about the middle of the dorsal side of this joint there is a single bristle of about the same 

 length as the dorsal side of the joint. Endopodite: First joint: The shortest of the three 

 ventral bristles is furnished at the middle with fine secondary bristles situated close together 

 and all roimd the bristle; these are about as long as the long secondary bristles on the two other 

 bristles; distally it has short hairs. On the two other bristles the short proximal secondary 



