studies on inmiiip Ostracods 188 



First joint: In all the forms of this sub-family examined by me the bristles were confined to a 

 single group of four bristles, placed ventero-distally on the joint; in exceptional cases this group 

 contains a somewhat larger number of bristles (the genus Crossophorus, see G. S. BRADY, 

 1880, pi. XXXVIII, fig. 6). The length of these four bristles was, as a rule, fairly constant 

 in the species investigated by me; apart from a rather slight individual variation they had 

 in most of these species about the following proportions: The two ventral were either about 

 the same length or of somewhat different lengths, comparatively long, about as long as or 

 somewhat longer or shorter than the length of the posterior side of the second endopodite joint; 

 of the two remaining bristles one was about as long as the proximal breadth of the second endo- 

 podite joint, the other was exceedingly short, sometimes rather difficult to get sight of. Second 

 joint : This joint is armed anteriorly with a larger or smaller number of bristles placed closely 

 together, of which the proximal ones are always sitxiated a little way from the proximal boundary 

 of the joint and the distal ones somewhat from the distal boundary. Among these bristles there 

 are some, situated on the anterior edge of the joint, with short and fine hairs; others, situated 

 on the medial side of the joint, mostly somewhat posteriorly of the former bristles, are generally 

 comparatively shorter than these and fitted with rather fine or more or less powerful hairs or 

 spines, placed closely together and arranged in the shape of a feather; these latter bristles seem 

 presumably to function as a sort of cleaning organ. Posteriorly this joint has always only a few 

 short, generally naked or almost naked bristles, placed distally to the middle of the joint. Of 

 these bristles the two distal ones are always situated close to each other; in some of the species 

 of this sub-family described in this treatise the medial one of the two bristles last mentioned 

 showed sexual dimorphism, being a little, sometimes considerably, more powerfully developed 

 in the males than in the females [see figs. 12 and 13 of Cypridma (Vargida) norvegica]. The 

 little end joint is most frequently (as in the sub-family Philomedinae) furnished with seven 

 bristles, of which even the longest are relatively short, as a rule not exceeding half the length 

 of the second endopodite joint. The relative strength and the mutual proportion of these bristles 

 is subject to rather great variation; in most cases, however, the two middle ones are claw-shaped, 

 a good deal more powerful and somewhat longer than the rest; the three posterior ones are, 

 on the other hand, weak, the most posterior one, as a rule, even exceedingly weak and short; 

 of the two situated anteriorly one is, as a rule, more or less claw-shaped, the other weak. 



Maxilla: Without or at any rate with only scarcely discernible sexual dimorphism. 

 — Protopodite: The basale is rather small or of moderate size and most often more 

 or less closely united to the first endopodite joint. The three well-developed masticatory 

 processes are most frequently immoveably joined to the procoxale and the coxale. Only in 

 exceptional cases is the part they all emerge together from developed as an appendage with an 

 independent power of motion (see the sub-genus Cypridinodes in this treatise). The species 

 of this sub-family investigated by me showed the following numbers of distal bristles on the 

 masticatory processes : On the first masticatory process 7 — 13, on each of the second and third 

 processes 5 — 7 bristles. These bristles are modified somewhat differently in the different 

 species, but within each species they show, on the other hand, a rather striking constancy; they 

 are often armed at about the middle with rather long and stiff, secondary bristles arranged 



