studies on marine Ostracods 741 



rows situated close together, from seven to nine in each row; in the specimens investigated 

 by me the number in the inner row was always seven. The length of these bristles is somewhat 

 less than or equal to the total length of the first and second joints. The longest of the bristles 

 on the end joint is about twice as long as this limb, the next longest is about a third or somewhat 

 more shorter than the former one. The middle of the three shorter ones is about as long as the 

 total length of the two proximal joints of this antenna; The ventral one is about half 

 this length, the dorsal one still somewhat shorter. The dorsal one of the three shorter 

 of these bristles has in most cases short, fine hairs, the others are bare or almost bare. For the 

 chitinization of the fourth joint see p. 739 above. AU the joints are quite bare. 



Second antenna: — The protopodite is about '/o mm. long. E x o- 

 podite: The proportion between the length of the protopodite and that of the exopodite 

 is about 5 to 3. The proportion between the length of the first joint and the total length of the 

 eight distal joints is about 2 to 1. The eighth joint is well developed, about as long as the next 

 preceding joint. The first joint is bare; its ventero-distal bristle is of the ordinary type, more 

 or less straight, about as long as the total length of the two or three following joints, verv weak 

 and bare. The natatory bristles on the second to the eighth joints are all of about the same 

 length — the distal ones are only slightly shorter than the proximal ones — about a quarter 

 to a third longer tlian this branch. They agree with each other in their type as well; the distal 

 part, about a fifth to a seventh of the length of the bristle, is bare and hyahne, but only very slightly 

 or not at all lancet-shaped (sensory organ) ; proximaUy of this part the bristles are furnished 

 with comparatively long natatory hairs almost right down to the base. The end joint has onlv 

 two bristles. The ventral one of these is about as long as this branch and is of the same t^'pe 

 as the natatory bristles on the preceding joints; the dorsal one is short, about as long as the total 

 length of the three to five distal joints, and bare. E n d o p o d i t e (figs. 21 and 22): The a- 

 and b-bristles on the first joint are bare, comparatively short and weak; the longer one is about 

 as long as or somewhat longer than half the length of the second joint, the other is about half 

 as long as the longer one or somewhat more. Second joint: This is about half as long as the first 

 joint, rather powerful and somewhat rounded on the right endopodite, somewhat more oblong 

 on the left. This joint has a rounded or somewhat broadly conical smooth verruca antero- 

 distaUy ; this verruca is rather powerful on the right, rather small and weak on the left endopodite. 

 Of the f- and g-bristles one is about as long as or somewhat longer than the shell, the other is 

 about a third of this length or somewhat more; they are both rather powerful proximally and 

 hyaline distally, narrow and bare or sparsely furnished with short hairs. The end joint on the 

 right endopodite is rather narrow, and is about equally thick throughout its length; it forms 

 an acute angle, its proximal shank being more or less straight, its distal shank, which is somewhat 

 longer than the proximal one, is evenly curved; it is distally rounded and has a few rather 

 powerful transverse ridges. Of its three bristles one is short, about as long as the width of the 

 joint, and bent into a hook; the two others are moderately long, one about as long as the proximal 

 shank of the joint, the other about twice as long or somewhat more. All these three bristles are 

 bare and narrow, somewluit ilattened distally. On the left endopodite this joint is about as 

 long as the proximal shank of the end joint on the right endopodite; its bristles too have the 



