184 CALIFORNIA ACADEMY OF SCIENCES. [Proo 3D Ser. 



Unfortunately this interesting species is known from a 

 single imperfect specimen, brought up on a stone from 

 about 100 fathoms in Monterey Bay. The posterior seg- 

 ments back of the twenty-fifth are wanting, also the palpi, 

 and one dorsal and one ventral peristomial cirrus. The 

 striking differences in size between the head cirri and the 

 dorsal cirri, between the dorsal and ventral seta?, are the 

 notable points in the external structure of this form. The 

 cirri and elytra are very readily detached. 



Family V. SIGALIONID^. 

 Peisidice, gen. nov. 



Body short, tentacle and the single pair of peristomial cirri identical in size 

 and shape, large and conspicuous, longer than prostomium. Palpi short, 

 not reaching beyond tips of peristomial cirri; no antennse; no dorsal cirri. 

 Dorsal rami of parapodia very small, bearing slender, fine-pointed, serrulate 

 setae. Ventral rami with much longer, stouter, compound seta?. Elytra 

 not meeting across dorsum; exposed portion of latter, and upper surfaces of 

 elytra coated with minute sand grains. Elytra borne on alternate somites, 

 papillated on their external and posterior margins. Anal cirri two. 



This genus, of which only a single species is known, 

 differs from Pholoe and Psammolyce, to which it is evi- 

 dently near akin, in the possession of only a single pair of 

 peristomial cirri, and in the regularly alternating sequence 

 of the elytra, whereas in Pholoe and Psammolyce they are 

 borne on every somite after the twenty-third and twenty- 

 seventh respectively. The body is likewise shorter, and 

 the somites few (not over forty in known species). 



Peisidice aspera, sp. nov. 

 Plate IX, Figs. 56-59; Plate X, Figs. 63, a-d. 



Body elongate-elliptical, semiterete, equally and evenly rounded at both 

 ends, its contour determined all around by the elytra, which cover over both 

 head and parapodia. Wide median stripe of dorsum bare for nearly entire 

 length; like the upper surface of elytra coated with sand grains. 



Prostomium globular, bearing in front a large papillate tentacle (fig. 56), 

 enlarged at the base, considerably swollen distally, and ending in a 

 filiform tip. Single pair of peristomial cirri extremely similar to tentacle. 

 Palpi short, stout, evenly tapered to a fine point, annulately grooved. Eyes 



