4;')^ TAdi-: SKOC.siiKliO 



about four to ten such long teeth were observed, scattered, situated at about equal distances 

 from one another; on the posterior main claws they become fewer and fewer and shorter and 

 shorter; in some species, however, they are rather short even on the anterior claws. The main 

 claws, at least the anterior ones, are furnished dorsally with short hairs. Claws nos. 2 and 3 

 are very finely serrated dorso-distally; I cannot say with certainty whether a similar serration 

 occurs in all the species described in this treatise, as this part of the claws is often rather con- 

 siderably worn. The posterior claws are finely pectinated. Sometimes the posterior claws are 

 finely annulated and on account of this they are exceedingly like bristles; this character cannot, 

 however, be used as a criterion in classifying the claws into main claws and secondary claws, 

 as it varies, at least in a number of species; in some forms there seems to be no annulation at all. 

 The lamellae often have short, fine hairs behind the claws. 



Male: — In some species it has the same number of claws as in the female, in others 

 it has slightly fewer. It is practically impossible to discover any division into main claws 

 and secondary claws. The first claw is, at least in a immber of species, somewhat more slender 

 and somewhat more boldly curved than in the female. The equipment of teeth on the claws 

 is somewhat weaker, especially on the first claw; this claw is almost entirely unarmed; its 

 distal c[uarter is even quite smooth. 



The upper lip is small and has two lobes; cf. (4. (). Sai;s, 1887, pi. V, figs. 4 and .5. 

 It has a very small field of glands. 



The rod-shaped organ is rather long, of moderate breadth and rounded distally; 

 its shape is somewhat irregular, most often somewhat broader at the middle; unjointed. In most 

 of the species described below of about the same type as that reproduced in fig. 11 for A. OJdini. 



The lateral eye s are most often well developed ; see below, A. ahyssicola. 



Gills: — These are of quite the same type in all the species I have investigated. 

 Cf. G. O. Saks, 1887, pi. VI, figs. 6 and 7. There are fourteen of them, seven in each row. 

 They are all of about the same type, rather long and broad lamellae, of uniform width and more 

 or less well rounded distally. 



Special terminnlogy: — Shell: — The list inside the posterior margin of the shell is 

 called ,,the spine-bearing list". 



For the terms for the distal bristles of the first antenna see the special 

 terminology of the family. 



M a n d i b 1 e: — The s c y t h e - s h a p e d j) r o c ess: The spine which is directed 

 proximally on the distal part of the ventral margin and which is characterized by the fact that it 

 is continued on the lateral side of the process by a low, bow-shaped ridge, armed, like the s{)iiu', 

 with a close series of stiff, rather short hairs, is called ,,the main spine". The protuberances 

 and spines on the ventral edge proximally of the main sjjine are called ..ventral spines". The 

 serrate teeth of the dorsal edge are called ,,the dorsal serrate teeth". The bristle distally of 

 these serrate teeth is called ,,the dorsal bristle". The backward pointing pro- 

 cess: The three or four bristles situated distally on this process, which are characterized 

 by the fact that their secondary spines become weaker and weakei' distally are called ..the 



