454 TAOE slv'OOSP.Knr; 



remaining one of these three bristles is somewhat shorter tlian the former ones and has in most 

 cases short, tine hairs; it is rarely provided at the middle with a number of long secondary bristles. 

 Antero-distally this joint is in exceptional cases furnished with powerful chitinous spines 

 (cf. A. spinifera, fig. 10). The second joint has postero-distally three rather long bristles with 

 short, fine hairs; two of these bristles are situated close to each other somewhat distally of the 

 third. The proportions between these bristles were subject to only slight variation in the species 

 investigated by me; one of the two distal ones and the proximal one are either subequal or else 

 the latter is somewhat longer; the remaining one of the two distal bristles is considerably shorter 

 than the two former ones and is also often characterized by being somewhat curved dorsally. 

 Along the anterior edge of this joint there are a rather large number of bristles. Among these 

 may always be noticed four powerful and rather long ones, in most cases subequal, situated 

 at about equal distances from each other along the whole of the joint and generally sparsely 

 provided with short and fine haii's, sometimes apparently even quite bare. These four bristles 

 are called the ,,main bristles" in this treatise and are denoted proximo-distally with the letters 

 a — -d. Proximally of and close to the proximal one of these bristles, the ,,main bristle a", there 

 are from one to a small number, different in different species, of rather weak bristles with 

 short, fine hairs or bare, often rather considerably shorter than the main bristles. Between the 

 nuiin bristles b and c there is in a number of species a rather weak bristle with short, fine hairs. 

 This bristle is of rather considerable length, in most cases, however, not quite so long as 

 the main bristles; in a number of species it is quite absent. Between the main bristles c and 

 d there is in all the species investigated by me a similar rather weak bristle with short, fine hairs; 

 this bristle is often about as long as the main bristles. An additional bristle of this sort, but 

 somewhat shorter, was always observed distally of and just near the main bristle d. Finally 

 there is anteriorly on the medial side of this joint a greater or smaller number of moderately 

 long or rather short cleaning bristles, characterized by being furnished distally with close, rather 

 short, in most cases rather powerful secondary bristles, arranged in the shape of a feather. These 

 bristles are partly arranged in a few more or less distinct rows running slantingly ujiwards and for- 

 wards. On the species investigated by me I have always seen a row of this sort, running within 

 the main bristle c. In these rows of bristles the anterior bristles are somewhat, sometimes even 

 considerably, longer and more powerful than those situated farther back. The cleaning bristles 

 vary somewhat within the species both with regard to number and position; they may, however, 

 be used to some extent as a character of the species. The end joint has six bristles, of about the same 

 type and position in all the species investigated by me. The anterior one is developed as a power- 

 ful claw. Three have about the same type and length as the main bristles of the second endo- 

 podite joint. Of the two remaining ones, both rather weak, with short hairs, one is situated 

 close to the claw, the other between the two posterior of the three long and powerful Ijristles; 

 the former of these two bristles is always somewhat longer, the latter always somewhat shorter 

 than the claw. Pilosity: The second endopodite joint has numerous groups of short, fiiu", stiff 

 hairs on the inner side. 



Male: — As has been pointed out above, the male mandible agrees in all essentials 

 with that of the female. It seems to be too early to try to generalize the dimorphism, because of the 



