studies on niariiie Oslracods 651 



First antenna: — The first joint is about a third shorter than the second; cf. 

 the accompanying fig. 4. E-bristle: This is about a third longer than this limb and has a distinct 

 knee somewhat distally of the middle. Just proximally of this knee there are two rows of rather 

 narrow, proximally pointing spines, which are in most cases pressed rather close to the bristle. 

 The distal parts of these spines are hyaline and their shape is exceedingly difficult to ascertain 

 with any certainty; as far as I could discover the distal part is about as wide as the proximal 

 part and is not furnished with any appendage that resembles a suctorial organ. In the specimens 

 investigated by me there were fourteen or fifteen spines in each row, all arranged in pairs; cf. 

 the accompanying fig. 5. (In G. W. MOller's pi. XVII, fig. 34. 1906 a, there are, however, 

 only eleven spines, and G. H. FowLER gives the number as from eight to twelve; cf. pp. 655, 656 

 below.) The distal spines are rather short and are situated rather close together, the other are 

 somewhat longer and more sparse the more proximally they are situated. Except for these 

 rows of spines this bristle lias distally no ecpiipment at all (there are consequently no distallv 

 pointing spines such as are found distally of the suctorial plate in C. elegans). The part distally 

 of the knee is narrow. Proximally of the rows of spines there are on the anterior side of this 

 bristle sparse, exceedingly short secondary bristles (scarcely perceptible with Reichert's ocular 4, 

 Leitz's immersion Vij). The b- and d-bristles are subequal and somewhat shorter than the 

 e-bristle; they have no distinct knee and are furnished with rather few or a moderate number 

 of short, fine, distally pointing spines situated about opposite the distal pairs of spines of the 

 e-bristle; cf. the accompanying fig. 6. These two bristles are also narrow and bare distally. 

 None of these three bristles has pad-like formations. The a-bristle is very long, rather slightly 

 shorter than this liuib, often bent at an angle proximally but otherwise in most cases more or 

 less straight; it has no accessory saccules. The c-bristle is straight and short, about a third or 

 a half the lenirth of the capitulum of the rod-shaped organ. All the joints are quite bare. 



S e c o n d a n t e n n a : — P r o t o p o d i t e: In specimens with shells about 1,45 mm. 

 this measured about 0,7 mm. Kxopodite: The proportion between the length of this 

 branch and that of the protopodite is about 11 : 20 or 12 : 2(». The proportion between the 

 length of the first joint and that of the eight following joints is about 3:1. The proportion 

 between the length of the longest natatory bristles and that of this branch is about 4 : 3 or 5 : 3. 

 The first joint has about the same shape as is reproduced below for C. serrulata, but is not 

 (juite so wide; proximally it has a rather sparse longitudinal row of short, fine spines, of about 

 the same type as in C. symmetrica (cf. my fig. 12 of this species), but with far fewer spines. 

 1*] n d o p () (1 i t e: First joint: The processus mammillaris has no distal verruca. The a- and 

 b-bristles have short, fine hairs. Second joint: The c- and (l-l)ristles are comparatively short, 

 in most cases rather considerably shorter than this joint (but not always so short as in the accom- 

 ]ianving fig. 7); they ha\'e short, fine hairs or are almost bare. The e-bristle is comparatively 

 well developed, about half as long as the two last-mentioned bristles or sometimes even somewhat 

 longer. The g-bristle is about as long as or in most cases somewhat shorter than the length 

 of the protopodite, the f-bristle is rather slightly shorter; the g-bristle is in most cases furnished 

 with sparse, exceedingly short hairs, the f-bristle is bare; none of these is decidedly swofd- 

 shaped. Third joint: The clasping organs are of the types reproduced l)y G. \V. ^li'l i.KR, 1906 a. 



