1905.] NATURAL SCIENCES OF PHILADELPHIA. 559 



This species presents an interesting combination of characters' which 

 weaken one's faith in the adequacy of some recent generic definitions. 

 Indeed, it is doubtful whether this species should not go into the'genus 

 Eudistyla. The entire structure of the collar agrees closely with Miss 

 Bush's description of the organ in that genus; the uncini and setae 

 are almost counterparts, and Johnson's figures of those of Eudistyla 

 (Bispira) polymoiyha, with which the preliminary determination associ- 

 ated these specimens, would answer almost equally well for the present 

 species. The eyes and the dorsal wings of the palpi or branchiarbases 

 are also features of similarity. But the absence of any pronounced 

 ventral prolongation of the branchial bases and the total absence of a 

 spiral twist to the latter, in the writer's Ofjinion, more than overbalance 

 those more trivial characters. The shortness of the branchiae may 

 suggest the possibility of their having been injured and in process of 

 regeneration, but a careful study has brought to light many reasons for 

 rejecting this view. • 



The type and co-type were taken July 11, 1903, at station 4,247 in 

 Kasaan Bay, Prince of Wales Island, in 95-114 fathoms, in a bottom 

 of mixed mud, sand and broken shells. 



Pseudopotamilla occelata sp. nov. PI. XXXVII, figs. 8 to 14. 



From the other species described in this paper the present is distin- 

 guished by its great length and numerous and conspicuous eyes. The 

 type measiu-es 130 mm., of which the branchiae are 18 mm. and the 

 thorax 11 mm. long. A still larger specimen from the same station 

 is nearty 20 mm. longer. 



The branchial bases are stiff, high and prominent, of uniform height, 

 provided dorsally with notched wings, and ventrally with a slightly 

 involute thin membrane. Full-grown specimens possess 21 to 24 

 pairs of branchiae, small ones 60 mm. long from 17 to 20. They are 

 moderately long, the dorsal somewhat exceeding the ventral, and en- 

 tirely without a connecting membrane. The stems are rather stout, 

 rounded externally and provided with a slightly raised line on each 

 margin just external to the bases of the barbs. The latter are rather 

 short and well separated toward the base of the stems, but near the 

 distal end become very slender, about three times as long as the bksal 

 ones and much crowded, leaving a very short thick tip of the stem 

 which also bears minute budding barbs of decreasing length almost to 

 the extreme end. 



Very conspicuous are the rich dark brown eyes, which are very uni- 

 form in size and large (about ^ the diameter of the stem), elevated and 

 bulging; all are on the margin of the external surface that lies nearest 



