284 PROCEEDINGS OF THE ACADEMY OF [April, 



latter becomes more distinct and larger than the other branchial 

 filaments and curves somewhat dorsad into a suberect position 

 (fig. 102). The remainder of the postsetal lip then divides into the 

 filaments of the digitate gill, the ventralmost filament of which retains 

 a trace of the foliaceous condition in a small basal wing. Otherwise 

 the branchial filaments resemble the clorsalmost filament or cirrus, and 

 where best developed only equal the foot in length and spread in a 

 palmate fashion (fig. 103). On the type there are two filaments at 

 X, three at XIII, continuing with three or occasionally four to XLIX. 

 The filaments increase in length to about XL and then rapidly diminish 

 without change in number to XLIX, at which segment the dorsal one 

 alone remains. It bears a small basal wing and remains quite promi- 

 nent for many segments and finally after reduction to a small post- 

 setal papilla continues to the end. A slightly larger cotype has two 

 branchial filaments at VIII, three at XVI, four or rarely five between 

 XX and XLII and three from XLII to LII. In the postbranchial 

 region the parapodia (fig. 104) are more slender and relatively more 

 prominent, cylindroid with the end slightly cleft into presetal and 

 postsetal lips, the latter a subcorneal papilla. A minute notopodial 

 papilla at the dorsal base of the neuropodium of all segments. 



Neuropodial acicula black with pale bases, usually four, slightly 

 tapered to blunt tips which reach, but ordinarily do not project 

 beyond, the surface. Notopodial acicular fine fibers which pass from 

 the segments above the parapodia strongly ventrad, curving into the 

 notopodial tubercle. 



All seta? have black or dark brown stems and pale ends, which on 

 the limbate setae includes the entire blade. All setae are simple, and 

 limbate seta? and crochets occur together on all parapodia, the former 

 being more numerous on anterior, the latter on posterior parapodia. 

 All are very brittle and, owing to the frequency with which they are 

 broken, the exact arrangement was not determined. At least one 

 crochet occurs in the subacicular fascicle of III along with three or 

 four limbate setse, of * which an equal number exist in the supra- 

 acicular fascicle. At X there are four supra-acicular acute limbate 

 setae, six subacicular limbate crochets and below these two more acute 

 setae. At XXV the numbers are respectively seven, five and one. 

 On posterior parapodia the usual arrangement is one acute seta and 

 one crochet in the supra-acicular fascicle and four crochets in the 

 subacicular fascicle. 



The pointed setae (PI. XIX, fig. 105) are of the usual bilimbate type 

 and either simply or sigmoidly curved. Some of those in the dorsal 



