722 TAGB SKOGSBERG 



few scattered moderately long or short bristles. The glands are as described by G. W. MtlLLER 

 for C. ■plintMna; just ventrally of the rostral incisur there is on both valves a group of several 

 large lateral glands. Seen from inside: Selvage (see the appended figs. 3, 4, 5): This 

 is of the same type as is described above for C. borealis. There is no distinctly developed hinge- 

 socket or hinge-tooth at the posterior dorsal corner of the shell. 



First antenna (see the appended fig. 7): — E-bristle: This is somewhat longer than 

 this limb and is bent at a decided angle at or somewhat proximaUy of two thirds of its length. 

 Just proximally of this bend there are two weU separated rows of strong, smooth spines, pointing 

 somewhat proximally ; there are about seventeen or eighteen spines in each row (see the appended 

 fig. 8). The spines in these rows are either placed in pairs or else there is weak or even complete 

 alternation. The distance between the distal spines is about as great as or somewhat more than 

 the width of these spines at the base; the proximal ones are situated somewhat closer together 

 than the distal ones. All the spines are of the same type; the distal ones are, however, somewhat 

 larger than the proximal ones; seen from the side they are bent somewhat proximally and are 

 pointed; if they are strongly compressed they appear to be flattened and somewhat rounded or more 

 or less abruptly cut oft' distally; see the appended fig. 9. Otherwise this bristle is quite bare. 

 Distally of the rows of spines it is slightly sword-shaped. The b- and d-bristles are subequal, 

 either about as long as the e-bristle or somewhat shorter (sometimes somewhat shorter than in 

 the appended fig. 7). The b-bristle, or else both these bristles, are bent at a distinct angle at 

 about the corresponding place as the e-bristle. Both have about opposite the spines of the 

 e-bristle a varying number (from about 5 — 25 were observed) of short, weak, distally pointing 

 secondary bristles. Distally these bristles are narrow or at any rate only very slightly sword- 

 shaped; both of them are without any pad-like appendages. The a- and c-bristles are subequal, 

 about a quarter of the length of the the e-bristle; the c-bristle is straight, the a-bristle more 

 or less rolled up; the a-bristle has a more or less weakly developed accessory saccule. All the 

 joints are quite bare. 



Second antenna: — Protopodite (see the appended figs. 11 and 13) : 

 In specimens with shells 4,0 — 4,1 mm. long this limb measured 1,6 — 1,7 mm. E x o p o d i t e 

 (see the accompanying fig. 12): The proportion between the length of this branch and that of 

 the protopodite is about 11 : 20. The proportion between the length of the first joint and the 

 total length of the eight following joints is aboiit 10 : 4 — 5. The proportion between the length 

 of the longest natatory bristles and that of this branch is about 15 — 17 : 10. The first joint 

 is furnished proximo-dorsally with a single dense longitudinal row of short, fine spines along 

 about a quarter or a third of the length of this joint and close to this row there are a rather 

 large number of scattered spines of the same kind and size. Endopodite (see the appended 

 figs. 13 and 14): First joint: The processus mammillaris has a small distal verruca. The a- and 

 b-bristles are bare. Second joint: The c- and d-bristles are not inconsiderably shorter than this 

 joint and are bare. The e-bristle is short. The g-bristle is about one and a half times the length 

 of the protopodite; the f-bristle is about a qiiarter shorter. Both these bristles are weakly sword- 

 shaped distally; the g-bristle has short hairs, the f-bristle is often bare. End joint: Clasping 

 organs: These are of the types reproduced by G. W. MtlLLER. The right organ may sometimes 



