254 PROCEEDINGS OF THE ACADEMY OF [April, 



basal enlargement and a slender style about three times as long as the 

 foot. 



Neuropodial acicula two or three simple, straight, tapered rods with 

 the ends pale and the middle brown or black. Posteriorly there is 

 only one of these, the distal end of which projects freely. No notopo- 

 dial acicula. 



Branchiae (PL XVI, fig. 30) remarkable for their large size and 

 restriction to nine segments (X-XVIII inclusive). The first on X 

 has five fully developed filaments and the number on the others varies 

 from five to seven. Each consists of a short, stout, tapered trunk 

 arising from the dorsal side of the base of the notocirrus and curving 

 dorsad over the back, its distal end abruptly bent to form the last 

 filament, parallel and nearly equal to the others, which are slender 

 and tapered and nearly equal in length to the notocirrus with which 

 the ventralmost is coalesced at the base. The largest meet across 

 the dorsum. 



Setae of four kinds, all but the crochets colorless. Compound seta? 

 (fig. 32) form a dense subacicular fascicle of several rows, very numerous 

 anteriorly, fewer behind. The shafts are slender, curved, with the 

 ends enlarged, oblique and bearing a deep cleft or socket with finely 

 serrated borders. Appendages loosely attached, tapered from the 

 basal enlargement to the bidentate tip, remarkable for the length and 

 wide separation of the teeth ; detached front border finely denticulated 

 or striated and continued into the delicate hood. Supra-acicular 

 fascicle composed of a tuft of delicate simple capillary seta?, some of 

 which are prolonged as far as the end of the notocirrus and associated 

 with these on postbranchial parapodia a few very delicate pectinate 

 seta? w T ith 16 or 18 short mucronate teeth and one margin bearing a 

 slender filament (fig. 33). Posterior parapodia bear a single ventral 

 crochet of a yellow color and having the end bidentate and hooded 

 (fig- 34). 



Practically colorless and lacking notable iridescence, only a slight 

 greenish shimmer anteriorly. Jaws not dissected. 



The type, a female filled with ova, comes from station 4,431, off 

 Brockway Point, Santa Rosa Island, 38-40 fathoms, coarse gray sand, 

 yellow mud and rocks. 



ONUPHID^. 



The large number of species representing this family is noteworthy, 

 there being in the collection five species of Nothria, three of Onuphis, 

 one of Diopatra and two of Hyalincccia — no less than eleven in all. 



