studios on marine Ostrarofls 413 



a very few long secondary bristles. E n d o p o d i t e: The first joint has distally-posteriorly 

 only four bristles. The end joint has three a-bristles and three c-bristles; the d-bristles are 

 often subequal. 



Fifth limb: — This is very like this appendage in Ph. (Ph.) globosa. As a rule, 

 however, the equipment of most of the bristles seems to be somewhat more weakly developed 

 than in this species. 



Sixth limb: — This is very like that of Ph. (Ph.) globosa; we may add that the 

 epipodial appendage is represented only by three bristles and that the second joint of the exo- 

 podite has only seventeen to twenty bristles. 



Seventh limb (fig. 3) : — This has about the same relative length as the corre- 

 sponding appendage in Ph. (Ph.) globosa. There are, as in Ph. (Ph.) Lilljeborgi and rotunda, 

 three dorsal and two ventral cleaning bristles situated close together distally; proximally of 

 these there are from five to seven dorsal and four to six ventral bristles scattered irregularly. 

 The cleaning bristles are moderately long and difier somewhat in length from each other, varying 

 also to some extent from individual to individual and on the right and the left limb of the same 

 individual. They are furnished with three to seven bells cut off transversally distally, the 

 tongue of the distal bell being also cut off transversally. Proximally of the bells these bristles are 

 furnished with short, and in most cases rather fine, hairs, partly, at least, arranged in one or 

 a few wreaths; these hairs seem sometimes to be almost entirely lacking. The end comb consists 

 of eleven to fifteen teeth of the same type as is described for Ph. (Ph.) rotunda. The cavity 

 dorsally of the end comb is rather deep and is furnished dorsally with two rather small, clavi- 

 form, smooth chitinous pegs. 



Furca: — The five posterior claws have no long basal-medial bristles. Apart from 

 this the furca of this species agrees completely with this organ in Ph. (Ph.) Lilljeborgi. 



Rod -shaped organ: — This is of precisely the same type as that of Pli. (Ph.) 

 globosa. It is about 0,3 mm. long. 



The male is unknown. 



Remark: — This species is very closely related to Ph. (Ph.) assimilis G. S. Brady, but Hfiniifn to oihe 

 differs from it by the equipment of the endopodite of the second antenna and by having more 

 numerous cleaning bristles on the seventh limb. In addition, unlike the species just mentioned, 

 it has not the peculiarity that the older females break off the natatory bristles on the second 

 antenna. 



Habitat: — T i e r r a del F u e g o: Strait of Magellan; depth, 7 m. : 3 mature females 

 (The Swedish „E u g e n i c" - E x p e d i t i o n, 1851—1853); R. M. S., on slides. Off 

 Cape Valentyn; 12. III. 1896; depth, 270 m. ; bottom of dead shells: 1 mature female and 

 5 juvenes (The Swedish Magellan Exped.); R. M. S. 135. 



Type specimen: on slides in R. M. S. 



spertt's. 



