47fi TAGE SKOGSBERG 



Brooks's law. Remark: — As will be seen below, I found, besides mature females, three female larvae 



as well of this species from station no. 34 of the Swedish ,,A n t a r c t i c" Expedition. 

 Two of these larvae were 2,44 — 2,45 mm. long, the third was only 1,95 mm. If we assume — and 

 the assumption is supported by anatomical investigation — that these two classes of length 

 represent the two oldest larval stages, we obtain, by using BROOKS's law, a coefficient of growth 

 of 1,25 (2,44 : 1,95 = 1,25). If 2,44 mm. then is multiplied by 1,25 we get 3,05 mm., a value 

 which thus coincides with the length of the mature female. 



Habitat: — South Georgia: S. A. E., Station 34, ofi the mouth of Cumberland 

 Bay, lat. 54» 11' S., long. 36« 18' W. (type - 1 o c a 1 i t y); 5. VI. 1902; depth, 252—310 m.; 

 grey clay with scattered stones; temperature at the bottom, + 1.45" C: 4 mature females and 

 3 juvenes; R. M. S. 162. 



Type specimen on slides in the collections of the R. M. S. 



Asterope spinifera n. sp. 



Description: — Female: — 



Shell: — Length 2,55—2,6 mm.; length : height about 1,5 : 1; length : breadth about 

 1,7 : 1. Seen from the side (fig. 1) it is of about the same type as the shell of the preced- 

 ing species, from which it differs chiefly by having the posterior part dominating over the 

 anterior one in a somewhat more striking way, by the dorsal and ventral margins being somewhat 

 more strongly curved and by the rostral incisur being situated somewhat more dorsally. Seen 

 from beneath (fig. 2) it is also of about the same type as the shell of the species just men- 

 tioned, but is somewhat broader comparatively. Seen from within: Medial bristles: 

 Parallel to and somewhat within the anterior margin of the shell there is on the rostrum a distinct, 

 moderately close, row of moderately long, stiff bristles. Within this row there are on the rostrum, 

 in the incisur and on the part just behind the latter rather numerous stiff bristles, all scattered, 

 most of them moderately long, a number, especially amongst those situated farthest in, more 

 or less short. Along the middle part of the ventral margin of the shell there are a moderate 

 number or rather numerous moderately long or rather short, stiff bristles, either scattered 

 or arranged in a more or less distinct row running somewhat within the margin of the shell. 

 From a point somewhat in front of the ventral boundary of the spine-bearing list this row of 

 bristles is continued by a very close, distinct row of moderately long, stiff bristles, running about 

 parallel to and somewhat within the margin of the shell up to about half the height of the shell, 

 from where it is continued by a considerably more sparse row of rather short and weak bristles, 

 which continue right up to the dorsal boundary of the spine-bearing list (fig. 3). Apart from 

 these bristles there are usually no medial bristles on the part between the posterior margin of 

 the shell and the spine-bearing list. The spine-bearing list has not an undulated edge and is 

 provided with 35 — 38 hyaline spines of somewhat varying sizes and a very close row of rather 

 short bristles of somewhat different lengths; about four to six bristles were observed for each 



