studies on niarinc Ostrarods 453 



curves, are found both mi tlic lateral and tlic medial sides of the process; they are, however, 

 V(>rv much more mimerous on the lateral side. The striatory systems of the two sides cross, 

 because the striations on the medial side, which are also distinguished by having somewhat 

 coarser hairs, form a more acute angle to the longitudinal axis of the process. I have obser- 

 ved, however, that the two systems join each other, at least on the dorsal edge of the process. 

 The distal part' of theT'process has no striations; this part is covered laterally by a mat — 

 in most cases very thick — of short, very fine hairs. There are also often short, fine 

 hairs on the bristle of the dorsal edge. In addition there are some transverse rows of rather 

 short, fine hairs laterally-ventrally somewhat proximally of the middle of the process. Some 

 irregular lists (strengthening lists according to G. W. MULLER, 1894, p. 46) run in the longitudinal 

 direction of the process; these are in most cases not drawn at all in the figures given in this work 

 of mine. The rod-shaped process is rather narrow, not quite half as long as the scythe-shaped 

 process. Along the greater part of its length it is furnished with rather short, strong bristles; 

 on both the medial and the lateral sides of the process most of these bristles are arranged in 

 a rather small number (about three to six) of transverse rows; the ventral bristle in each row is 

 in most cases the longest, the others decrease fairly uniformly in length dorsally. The rod-shaped 

 process is blunt distally and is provided there with three or four short spines or bristles. Basale : 

 The backward pointing process is well developed and is furnished with a rather small number of 

 bristles (from six to eleven were observed on the species investigated by me). Of these bristles 

 the three or four nearest to the point of the process are rather long and powerful and are character- 

 ized by having numerous short secondary spines, arranged in two rows and placed close together, 

 along the greater part of their length ; these spines are rather powerful proximally and become 

 more and more fine distally (cf. fig. 9 of A. sfinifera). From one to five, in most cases from 

 three to five, of the other bristles are also most frequently rather long and powerful and are 

 characterized by having a greater or less number of secondary spines, arranged in two rows 

 and situated close together distally; the distal pair of these spines is the most powerful, extending 

 no inconsiderable distance distally of the point of the bristle; the others are rather short. The 

 remaining one or two bristles are short and weak, bare or provided with exceedingly fine, short 

 hairs. In the neighbourhood of these bristles a rather large number of unicellular glands have 

 tluMr openings on a more or less developed verruciform process. Dorso-distally this joint always 

 has two bristles with more or less short hairs; these bristles are, as a rule, considerably longer 

 than the anterior side of the first endopodite joint. Apart from these the dorsal side of the 

 second protopodite joint is quite without bristles in a number of species, in others it has a larger 

 or smaller number of these, characteristic for the species. Exopodite: The two ventero- 

 distal bristles of this branch are always very short. This branch is furnished dorsally with 

 exceedingly numerous short, fine hairs (the exits of the glands). Endopodite: The first 

 joint has only three ventral bristles. Of these the two posterior ones especially are very long; 

 they are in most cases somewhat longer than the anterior side of the endopodite and are always 

 furnished at the middle with a number of rather long and powerful anterior secondary bristles, 

 arranged in two rows; proximally of these secondary bristles there is in a number of species a 

 varying number of short secondary bristles; these two bristles have sliort. fine hairs distally. The 



