1903.] NATURAL SCIENCES OF PHILADELPHIA. 469 



orly, tapering gradually from end of anterior ^ both ways ; both dorsal 

 and ventral surfaces smooth, the former depressed between the dorsal 

 ends of the parapodia, by which it is sharply bounded, and than which 

 it is narrower, the latter wider, not depressed and passing gradually 

 at the sides into the parapodia. Somites rather long, uniannulate, 

 and, A\ith the exception of the first, very distinct and sharply n^arked 

 by deep furrows ; the first united broadly at the sides and by a narrow 

 median dorsal tract to the peristomium, posteriorly rather indistinctly 

 separated from the succeeding somite; it bears an achsetous parapodium; 

 last 7 or 8 somites becoming rapidly smaller and the last 3 appar- 

 ently achaetous. Pygidium prominent, expanded, somewhat funnel- 

 shaped, and looking obUquely upward; anus in its centre. 



Parapodia low but distinct, transverse lateral ridges equal to about 

 i of body circumference; anteriorly they are wrinkled and entirely 

 undivided, and pass without distinct boundaries into the ventral sur- 

 face, but sharply hmited dorsally where they rise above the level of 

 the smooth area; farther back the dorsal delimitation becomes less 

 and less distinct and the parapodium becomes somewhat differentiated 

 into dorsal and ventral portions, which assume more divergeat and 

 prominent positions on the dorsal and ventral quadrants as the height 

 of the body decreases. 



No brancliise are in situ, but a few very long slender and much coiled 

 filaments in the bottle probably belong to this w^orm, while very dis- 

 tinct scars clearly indicate their chsposition. Except about the last 

 10, each and every somite bears a pair of scars; anteriorly they are 

 very conspicuous, and the first, which is between the dorsal end of the 

 1st parapodium and the prostomimn and probably belongs to the latter, 

 is much larger than the others. For about the next 17 somites the 

 scars are at the extreme posterior margin of the somites and exactly 

 on the level of the dorsal ends of the parapodia, but farther back, as 

 the latter become less distinctly limited, the scars assume a progres- 

 sively lower and then more anterior position, until in the posterior half 

 of the body they are just behind the lowermost setae of the dorsal divi- 

 sion, or nearly at the middle of the parapodium. The posterior scars 

 become smaller but remain quite evident to the last. 



The setse present a striking contrast to those of C. ahranchiata owing 

 to the substitution in large part, for the dehcate capillary setse of that 

 species, of stiff, brittle, spinous setse which stand out in conspicuous 

 w^horls at the posterior end. In all parapodia the setae are arranged 

 in a single vertical rank of two groups, although anteriorly the interval 

 between is so small that from the exterior they appear to be continuous. 



