Sliidios on m^iriiio Oslriicods 4-).) 



comparativelv small miinhcr' of species of whicli l)otli inal<^ and Icnialc ate known. I 7-(>}Vi- the 

 reader to the descriptions of tlie species and will only point out here that variations have been 

 observed in the backward pointing process on the basale (in some species), the equipment of the 

 shortest of the three ventral bristles on the first endopodite joint, the bristles proximally of the 

 main bristle a of the second endopodite joint and tlie cleaning bristles of this joint. 



Maxilla: — P r o t o p o d i t e: On the procoxale and coxale there are two very 

 strongly, sometimes almost completely, reduced endites. Of these endites the proximal one was, 

 in all the species investigated by me, provided with four bristles, three of which were subequal, 

 rather long and powerful, the fourth, situatetl between the two proximal of the three former 

 ones, was rather weak and not quite half as long as these. The distal endite is in most cases 

 furnished with only three bristles, which are sometimes subequal and of about the same length 

 and strength as the three long bristles of the proximal endite, while sometimes the middle one 

 of them is somewhat shorter. In only one species, A. oculata, was there observed between the 

 two distal of these three bristles a bristle of about the same kind as the short bristle on the 

 proximal endite. The long bristles on these endites always have, at least in parts, rather long 

 hairs, of which those that issue from the distal part of the bristles are arranged in the 

 shape of a feather and are ratfier coarse. The one (or the two) short bristles are bare or have 

 very fine and short hairs. The posterior bristles in the baleen are only about a third or a half 

 the length of the anterior ones. The baleen bristles are widened out distally somewhat in the 

 shape of a lancet and are pointed (not blunt as in pi. 5, fig. 15 a, G. W. Ml-LLER, 1894; 

 cf. p. 465 of this treatise of mine), somewhat boat-shaped (if I am not mistaken) and 

 furnished at the edge with exceedingly fine hairs, scarcely perceptible even with very strong 

 magnification (Reichert's oc. 4, Leitz's immers. ~); cf. fig. 14 of ^. Grimaldi. The posterior 

 l)ristle in the baleen is of about the same type in all the species investigated by me; it 

 is of moderate length, its distal part is somewhat lancet-like, inclined forwards and finely and 

 closely pectinated along the ventral edge; cf. fig. 15 of A. Grimaldi. On the outside of the 

 ]irotopodite there is only a single bristle; it is moderately long, and situated on the basale, about 

 half-way up the joint, beneath the epipodial appendage; it is of about the same type in all the 

 species investigated by me. On the inside of the protopodite there are a number of bristles, 

 which afford rather good characters for the species by their number and relative length. Dor- 

 sally, just in front of the fastening of the epipodial appendage, there is a single bristle; I was 

 iinahle to decide with certainty whether this issues on the coxale or on the basale. Dorsallv on 

 the distal part of the basale there is in most of the species one or a small number of bristles. 

 About half way along this joint there is ventrally one or a small number of bristles. A short 

 ilistance distally of this (them) there is in most cases a very short bristle, situated ventrally 

 on the joint between the baleen and a list-like medial part; this bristle is in most cases very diffi- 

 cult to observe with certainty on account of its small size and its concealed position. Finally 

 the basale has a rather long bristle ventrally and somewhat laterally close to the boundary of 

 the endopodite. This latter bristle is furnished with rather long and exceedingly fine hairs, 

 the other bristles of the protopodite are bare or have extremelv tine, short hairs. T h e e p i- 

 p o dial a p p e n d a g e, issuing presumably distally on the coxale, is compressed at the sides 



