344 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 10 



This is one of the smallest species of the genus. Length of a larger 

 specimen, fixed in the tube, is 16.5 mm without, 20.8 mm with, caudal 

 tail. The average length is 15 to 20 mm. The entire body is pale or 

 colorless save for a few, scattered, longitudinal, dark splashes on the 

 opercular stalk and thoracic region. The opercular spines and other setal 

 structures are pale amber in color. Some of the specimens show large, 

 extruded eggs, indicating sexual maturity. 



The opercular disk is circular when fixed free from the tube, other- 

 wise elongate or oval. Spines of the outer series are directed outward, in 

 a uniformly long, continuous circle; those of middle and inner rows 

 appear shorter but are actually about as long (pi. 34, figs. 66, 67, are 

 companion paleae), or those of the middle row may be somewhat shorter 

 and blunter (pi. 34, figs. 68, 69 are companion paleae from another indi- 

 vidual). Those of the middle and inner rows resemble one another more 

 closely than is usual in species of this genus. There are 17 or 18 pairs of 

 short papillae in a single series around the outer base of the opercular 

 crown; they are partly dark on the ventral side and almost entirely black 

 on the dorsal side. 



Oral tentacles are arranged in 7 ranks on a side, consist of 6 or 7 in 

 a row. Palpi are tapering, cirriform, exceed the oral tentacles in thickness 

 but not in length ; they are completely concealed from view by the over- 

 hanging tentacles. The oral aperture is bounded posteriorly by the thick, 

 glandular building organ, and immediately at the sides are the first pair 

 of neuropodia, each provided with a thick ventral cirrus adjacent to the 

 building organ ; I am unable to find setae in it. 



The second anterior thoracic segment has its ventral cirrus nearly in 

 contact with, but at the outer sides of, that of the first segment; it is 

 similarly pointed triangular, resembles the dorsal cirrus in shape and 

 size; its rami are provided with 7 to 10 simple, slender setae. A dorsal 

 branchia arises from its upper side, resembles those farther back. 



The 3 parathoracic segments are longer and thicker than those in 

 front. Paleae in each are arranged in a single row, increase slightly in 

 size and length from the first to the third segments, and their number 

 decreases gradually such that the first has 7 paleae on a side, the second 

 has 6, and the third has only 5. They are somewhat spatulate in shape, 

 with serrated edge (pi. 34, fig. 70). Abdominal segments number about 

 20; they decrease in width and length, from anterior to posterior direc- 

 tions. Abdominal uncini have usually 5 teeth, seen from the side (pi. 34, 

 fig. 71). 



