430 THE ANNELIDA POLYCHAETA. 



The ventral plates increase in length and decrease in width in going caudad, 

 as usual. Taken together they form a narrow band, the caudal end of which 

 is acutely narrowed. There are ten well-developed plates. In the para type 

 there is but one definite plate caudad of these, but in the type there are four or 

 five reduced ones which are not contiguous and are abruptly narrower. 



The notopodial setae are long, with the tips very slender; the two wings 

 are extremely narrow. The uncini have the usual general arrangement. They 

 are in a single series on somites five to eleven, inclusive, and in two closely inter- 

 locking series on the remaining thoracic somites. On the abdomen the series 

 are again single. The uncini are of about the same size as in tahoguillae, or a 

 little smaller. Above the main fang are numerous, slender, smaller ones arranged 

 in three more or less uneven series. On the convex side the plate abruptly 

 widens to form a conspicuous angular shoulder. On the opposite side the plate 

 is characteristically excavated adjacent to the inferior process. (Plate 79, fig. 9). 



The caudal end of the abdomen is simply rounded, not at all abruptly 

 narrowed or conically pointed. The anus is circular; its narrow, slightly ele- 

 vated border is radially furrowed, producing a series of contiguous, short, ridges, 

 or tubercles. 



Locality. Off Aguja Point, Peru, 20 m. N. W.: Sta. 4654 (lat. 5" 46' S., 

 long. 81° 31' 9" W.). Depth 1,036 fms. 12 November, 1904. Two specimens. 



NiCOLEA LATENS, Sp. nOV.^ 



Plate 79, fig. 10, 11. 



General color greyish yellow, with the first few somites above of a somewhat 

 reddish brown color. Setae colorless. 



The type has most of the abdomen broken off. The length to the end of 

 the thoracic region is 18 mm. The greatest width is 4 mm. The greatest width 

 is attained at the eighth somite, from where the body narrows gradually both 

 cephalad and caudad. This is also the region at which the body is deepest. 



The prostomium presents above the mouth a wide, short and thin mem- 

 branous fold weakly convexly arching between its ends. Its free margin is 

 weakly crenulate. Caudad of and parallel with this is the conspicuous, thick, 

 tentacular ridge, the anterior slope of which is crenulate in outline from many 

 subvcrtical furrows, which do not extend across the dorsal surface or ridge. 



' latere, to hide. 



