1911.] NATURAL SCIENCES OF PHILADELPHIA. 287 



projecting or projecting only slightly beyond the surface. Xotopodial 

 acicula obsolete, corresponding to the extreme reduction of the noto- 

 podia. 



Seta) moderate in number, disposed in a supra-acicular and a sub- 

 acicular fascicle, the former nearly horizontal, the latter vertical in 

 arrangement. At somite XV there are eight in the former, fifteen in 

 the latter, a number which is reduced posteriorly to three in each 

 group, of which the subacicular are crochets. All are dark bro^^^l at 

 the base, pale or colorless distally. Anteriorly acute setic (PI. XIX, 

 fig. 114) alone occur. They are long, slender, narrowly bilimbate and 

 slightly sigmoid with prolonged capillary tips. Those in the supra- 

 acicular fascicle longer than the subacicular, but otherwise similar. 

 On posterior parapodia they become shorter (fig. 115). It is impossible 

 to ascertain from the type alone at just what segment crochets appear, 

 but certainly none are present before somite L, and about LXX would 

 appear to mark the point of their appearance. They are slightly 

 stouter than the limbate setse, with slightly curved, not thickened 

 stems, ending in an imperfect small head enclosed in a delicate hood 

 (PI. XIX, fig. 116). 



Mandibles (PL XIX, fig. 117) rather delicate, flexible, soft, white 

 with black or dark brown apices and parallel dark bro\\ai lines on the 

 masticatory plates and more delicate brown lines and a heavy median 

 dark band on the carriers. The anterior half of the carriers is a broad 

 solid piece, the posterior half a pair of slender slightly divergent stems. 

 Masticatory plate a continuous, narrow, hard, curved band bordering 

 the free end of the carrier and obscurely toothed at the apex. Maxillae 

 (PI. XIX, fig. 118) dark brown or black, opake. Forceps jaws with 

 base plate or carrier about two-thirds as long as jaws, ovate with a 

 constricted anterior end and straight hinge; the jaws with stout bases 

 and strongly curved ends. First dental i)lates (II) irregular and each 

 with only two large teeth on medial border. They are possibly 

 abnormal or much worn. The next plate (III) is small and narrow 

 with one large apical tooth, and the anterior plate (lY) is remarkably 

 large, triangular with a single stout tooth. 



Color uniform brown. 



This species is imperfectly known through a single specimen taken at 

 station 4,397, off 8anta Catalina Islands, 33° 10' 15" X., 121° 42' 15" W.. 

 2,196 to 2,228 fathoms, gray mud. 



Ninoe fusca is closely related to Ninoc simpla ]\Ioore jDreviousl}' 

 descril^ed from Alaskan waters. Both have the nuchal papilla and 

 simple unifilar gills and their set£e are closely similar, but they differ 



