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Third pair (PI. XIV, üg. 16): rami slightly unequal, the number of segments varying 

 from 9 in the shorter and 10 in the longer ramus, to 13 and 14 segments respectively in the two 

 rami. The segments are not very strongly protuberant, but only rounded, on their inner or 

 anterior face. Numerous hairs are disposed on each segment ; they do not form, however, such 

 dense tufts as on the segments of the 2 nd cirrus. Each segment, on its anterior face, is furnished 

 with a row of small but well-developed teeth, a second row of still smaller teeth being ordinarily 

 seen parallel to that along the margin, and at little distance only from it. In the larger 

 specimens of the var. communis from Java, the surface is even covered with several rows of 

 such small teeth, the size of which diminishes from the anterior face towards the other side of 

 segment. In these specimens, a row of somewhat stronger teeth is disposed along the upper 

 margin of each segment. Both rami show these teeth; they are nearly as strongly developed 

 in one as in the other. 



Groups of similar teeth are seen also on the lower segments of both rami of the 4 th cirrus. 

 I counted in one specimen, the 4 111 cirrus of which had over 20 segments, about a dozen segments 

 furnished with such a group of teeth, disposed on the surface near the anterior and upper 

 margins of the segment, but not on the anterior margin, as in the 3 vd cirrus. 



The 3 vd cirrus has a dense tuft of long delicate hairs disposed at its basis on the thorax 

 and directed backward. 



Fourth-sixth pairs (PI. XIV, fig. 17): have almost the same structure. In a large 

 specimen the two rami of the 4" 1 cirrus had respectively 22 and 24, of the 5 th cirrus 25 and 

 27, and of the 6 lh cirrus 26 and 28 segments. In a somewhat smaller specimen the number of 

 segments of the two rami of the 6 th cirrus had 25 and 26 segments, in a much smaller specimen 

 these numbers were 20 and 21 only. The segments are furnished on their inner faces with 

 from 4 — 6 pairs of spines, the middle segments having 5, and sometimes even 6 pairs of such 

 spines, whereas the terminal, as well as the lower segments, are furnished with 4 pairs only. The 

 middle segments are as a rule from 1 1 /., — 2 times as long as broad, the inferior segments are 

 about as long as broad and the terminal segments are over twice as long as broad. The sixth 

 cirrus shows a transverse row of small triangular teeth disposed along the distal extremity of 

 the lower segments. These teeth are developed much more strongly in the var. communis than 

 in the var. malayensis\ they probably grow somewhat stronger with the age of the animals. 

 These rows are already present at the extremity of the segments of the pedicel, and here consist 

 of 10 or more teeth; on the lower segments each row shows 6 to 7 teeth, the number decreasing, 

 until on the middle segments of the cirrus, only 3 or 2 of these teeth are observed. The posterior 

 margin of the segments of the pedicel is hirsute, a large number of extremely small teeth-like 

 spines being disposed along it. 



The penis bears a small pointed projection on the dorsal side near the basis. It is 

 not very long, is broad or thick at the basis, and strongly tapering towards the extremity. Few 

 hairs only are scattered over its surface. 



Geographical and bathymetrical distribution. This species seems to be 

 common in warm and tropical seas all over the world. In Darwin's Monograph the distri- 

 bution of the species and also of the varieties is given; the species, according to him, inhabits 



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