Studifis on marine Oslracods 537 



number of solitary glands, most of which are arranged in a rather distinct row (cf. fig. 6) and 

 a number situated irregularly; in the specimens investigated by me from 105 to 143 of these 

 glands were found on each valve: in most cases they were quite absent inside the rostrum and 

 along the dorsal third or half of the posterior margin of the shell. In preserved material one 

 often sees hyaline fibres attached to these glandular exits; these are certainly solidified secretions. 

 Outside these glands there are a small number of solitary glands, some opening inside and others 

 outside the margin of the shell. The joined part of the lamellae is narrow. The outer lamella 

 is not specially thin and is moderately strongly calcified; this lamella was brittle in a number 

 of the specimens investigated by me. 



First antenna: — This has five joints*. Between the first and second joint there 

 is in most cases a rather distinct ventrally open knee. The proportion between the lengths 

 of the joints seems fairly constant and is about as follows: 



I • II • III • IV • V = -•-•-•'• - 



The first joint has not disto-ventrally any verruciform process as in (all?) the males 

 of the genus Euconchoecia (this is presumably a genus character). The dorsal bristle of the second 

 joint is situated at about the middle of the joint; it is powerful, has short hairs and is compar- 

 atively long, being in most cases equal to the total length of the four distal joints of this antenna. 

 The bristles of the two distal joints vary somewhat in length. The e-bristle of the end joint is 

 about two or three times as long as this limb and is sometimes about as long as, sometimes 

 a little longer than, sometimes considerably shorter than twice the length of the a — d-bristles; 

 the e-bristle is only slightly or sometimes not at all widened along its distal half, and is furnished 

 with only a few hairs. All the joints are quite bare. 



Second antenna: — Protopodite: This is of moderate size; in specimens 

 with shells about 1,4 — 1,5 mm. long it attained a length of about 0,6 — 0,7 mm. Its distal- 

 lateral verruciform process varies somewhat in shape; it is often of the type reproduced in 

 fig. 9. Exopodite: This is rather slightly shorter than the protopodite. The proportion 

 between the lengths of the exopodite and the protopodite is about 6:7. The first joint is relatively 

 long; the relation between its length and the total length of the eight distal joints is about 4:2 

 or even 5:2. The eighth joint is rather well developed and almost as long as the immediately 

 preceding joints. The first joint is bare; its ventero-distal bristle is fairly straight and is about 

 as long as or somewhat longer than the second joint, annulated, bare or sparsely furnished with 

 exceedingly short hairs. The natatory bristles on the second to the eight joints are all of about 

 the same length — the distal ones are only slightly shorter than the pro.ximal ones and about 

 one and a third or one and a half times as long as the exopodite; their distal parts, about a fifth 

 or a sixth of the length of the bristles, are bare, hyaline, but very slightly or not at all \\idened 

 in the shape of a lancet (sensory organs) ; they are furnished with relatively long natatory hairs 

 almost down to the base. The end joint has thi-ee bristles: One of these is sparsely furnished 

 with short, fine hairs or is bare, and is about as long as the total length of the four distal 

 joints, the second is of the same type, but is, in most cases, somewliat longer than the eight distal 



* For Cii. JuDAYS statotnont about six joints on this antenna soo |). r>00 below. For the explanation of the 

 liiird joint sec p. 577 above. 



