studies on marine Oslracods ' 699 



(it is to be noted that the distal doulale row is here counted singly). C. Claus makes no direct 

 statement as to the shape of these spines; he only denotes the distal ones as ,,Hakchen", the 

 proximal ones as ,,Hakenspitzen". G. W. Mullbr denotes the distal ones as ,,kraftig, solid", 

 the proximal ones as ,,borstenf6rmig". As far as I could see (with Reichert's ocular 4, Leitz's 

 immersion Vij) the distal spines are of about the type reproduced in the accompanying figure 5, 

 i. e. they are furnished along the side that is turned towards the point of the bristle with a wing- 

 like appendage and with a more or less narrowly oval plate distallv; the more proximally these 

 ,, spines" are situated on the bristle, the smaller the wing-like appendage and the distal plate 

 become; on about the eighth to the tenth pair of spines these appendages are scarcely perceptible; 

 the proximal spines are narrow and pointed. Distallv of these rows of spines this bristle is 

 quite bare. (More or less distally pointing spines such as are found in several species of this 

 genus, e. g. C. oblonga, are thus quite absent.) Just distally of these rows of spines this bristle 

 is bent at a rather decided angle; the part of the bristle distally of this knee is not widened. 

 On the anterior side this bristle is almost quite bare. The b- and d- bristles are in most cases 

 bent at a rather distinct angle at about the corresponding place as the e-bristle and are not 

 widened distally; at about the corresponding place as the rows of spines on the e-bristle they 

 are furnished rather sparsely with short, exceedingly fine, distally pointing spines. None of 

 these three bristles has pad-like formations. The a-bristle is relatively long (see the accompanying 

 fig. 4); when it points backwards, it reaches in most cases to about the middle of the first joint 

 of this limb, sometimes it is rather slightly shorter or longer; it has no accessory saccule. The 

 c-bristle is quite short, about as long as or rather slightly longer than the distal height of the 

 second joint. This bristle is more or less straight; the a-bristle too is most frequently rather 

 straight, at any rate it is not strongly rolled up. All the joints are quite bare. 



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

 long this part attained a length of about 0,5 — 0,55 mm. The distal-medial verruca varies 

 in shape, being in most cases somewhat irregularly lobate. Exopodite: The proportion 

 between the length of this branch and that of the protopodite is about 1 : 2. The proportion 

 between the length of the first joint and the total length of the eight following joints is about 2 : 1. 

 The proportion between the length of the longest natatory bristles and that of the exopodite 

 is about 7 : 5. The first joint is in most cases quite bare, at least as far as I could decide with 

 Reichert's ocular 4, Leitz's immersion V12; sometimes, however, it is furnished proximo- 

 dorsally with more or less abundant weak spines. Endopodite: First joint: The processus 

 mammillaris has no distal verruca. The a-bristle has short, fine hairs, the b-bristle, which also 

 has short, fine hairs along the greater part of its length, was in all the specimens investigated 

 by me furnished with two rather long hairs somewhat proximally of the middle; in a number 

 of specimens there were from about two to four moderately long hairs close to the two long 

 ones. See pp. 703 — 706 below with regard to this character. Second joint: The c- and d-bristles are 

 in most cases somewhat shorter than this joint and have short, fine hairs, almost bare. The 

 e-bristle is extremely short (sometimes absent?). The g-bristle is about as long as or rather 

 slightly shorter than the protopodite; it grows gradually narrower distally and is furnished 

 with sparse short hairs. The f-bristle is of about the same type as the g-bristle, but is about 



