134 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 22 



fully everted. It measures 14 mm long, about one mm wide and consists 

 of 27 setigerous segments; there is no anal tube. Another specimen from 

 Long Basin measures 22 mm long and also has 27 segments. It resembles 

 those of the first lot except that pharynx, nuchal organs, and palpode arc 

 not extended. 



The prostomium is longer than wide, conical, and terminates in front 

 in a slender, conical or elongated palpode ; there are no eyespots. The 

 mouth is at the posterior ventral position, in line with the nuchal organs 

 and midventral. This region is set off from the first segment by a trans- 

 verse line but no segmental groove. The first parapodial segment is the 

 first visible one; it has lateral parapodia which are smaller than those on 

 successive segments. Others increase gradually in size and resemble short, 

 papillar lobes from which the long setal fascicles extend. The last 4 para- 

 podial segments are shorter, somewhat crowded, and followed by an 

 anal ring with a dorsal anal pore; there are no anal cirri or tube. 



Branchiae are present from the second parapodial pairs to the fifth 

 last segment and number 22 pairs. They are long, slender, cirriform 

 processes throughout (Plate 14, fig. 3). A broad, neural groove extends 

 throughout the length of the body; it is bounded on either side by ridges 

 marking the strong muscular bands. 



Setae are entirely slender, hairlike and project from the parapodia in 

 sparse, laterally directed fascicles. In the type specimen, and seen by 

 dissection in other specimens, the pharynx is observed to be a smooth, 

 ventrally directed epithelial pouch adorned with a series of 16 long cirri 

 arranged in a semicircle (Plate 14, fig. 3). This feature may distinguish 

 the species from others of the genus. The posterior region contains large 

 ova, seen through the surface epithelium. 



A. pallida resembles A. galatheae Kirkegaard (1956, p. 71) from the 

 Banda trench in 7250-7290 meters; both lack an anal tube. In the latter, 

 however, the body consists of 30 setigerous segments and branchiae are 

 present on all segments but the first one ; the proboscis is not modified as 

 in A. pallida. Another abyssal species is A. nybelini Eliason (1951, p. 

 135) from the North Atlantic Ocean in 4504-4600 meters. It measures 

 48 mm long by 2 mm wide and consists of about 45 segments, and has 

 a long anal tube. 



Ammotrypane pallida is known only from San Nicolas and Long 

 Basins and may be regarded as a deepwater form. 



Other small, immature or vegetative specimens of Ammotrypane 

 were taken in Santa Catalina and San Pedro Basins; these were earlier 



