410 Vniversity of California Publications in Zoology [Vol.16 



The shape of the bodj^ in Aphrodita cryptonunata is more slender, 

 ending in a narrow caudal region ; in A. parva the body ends poster- 

 iorly more obtusely. The neuropodia are more slender in A. parva. 

 The shape of the prostomium is also different in the two species. The 

 median tentacle is ver.y short in A. cryptoinmata; it is very long in 

 A. parva. The neurosetae of A. cryptommata are perfectly smooth, 

 without any hairiness; they are pillose with a prominent spur in A. 

 parva. The fimbriated organs in A. cryptommata differ from those of 

 A. parva and from any other known species by having four to five con- 

 spicuously long, finger-like lobes. The elytra are somewhat squarish 

 in A. cryptommata ; they are more rounded in A. parva. 



Description. — The body is ovately elongated, tapering towards 

 both extremities, more toward the posterior end (pi. 37, fig. 83). The 

 dorsum is arched, and the segmentation is well marked on the ventral 

 surface. The two specimens in the collection of the University of 

 California are 28 and 29 mm. long respectively. The width of the 

 body is 16 mm. from tip to tip of the setae, and 10 mm. between para- 

 podia. The greatest width of the body is between segments 10 and 

 11. The width decreases thence towards both ends. The ventral 

 surface is thickly covered with prominent, capped papillae. There 

 are thirty-eight segments. 



The prostomium (pi. 34, fig. 39) is semiglobular, having the width 

 equal to the length. The ocular protuberances are prominent, each 

 bearing a pair of minute eyes, of which the dorsal pair only is visible 

 from the dorsal surface. The median tentacle is very short, consist- 

 ing of a short cirrophore and a short style. The palpi are white, 

 stout, slightly grooved longitudinally, tapering gradually toward the 

 distal end, and are covered with fine cilia. Their length is about five 

 and one-half times the length of the prostomium. The fifteen pairs 

 of eh'tra are thin, squarish in shape (pi. 34, fig. 40), strongly over- 

 lapping, and completely covering tlie dorsum. They are sparsely 

 covered with papillae and fine venations radiating from tlie point of 

 attachment in all directions. 



The fimbriated organs have from four to six long, smooth, finger- 

 like projections (pi. 34, fig. 47). 



The parapodia are of the usual shape characteristic of the genus 

 (pi. 34, fig. 49). The neurosetae are smooth, with abruptly narrow- 

 ing ends terminating bluntly. There are two dark-brown, stout neu- 

 rosetae in the dorsal series (pi. 34, fig. 43) ; five finer setae from the 

 middle series (pi. 34, fig. 42) equal in structure to the former; eight 



