ADMETELLA DOLICHOPUS. 69 



caudal direction; each narrows strongly from base to near the middle of the 

 length, the proximal region in outline subtriangular, its dorsal side strongly- 

 slanting, its ventral horizontal and continuous in direction with that of the 

 remaining more slender portion of the parapodium. Neuropodium long, but 

 little varying in thickness in different parts of its length except toward the distal 

 end where subconically narrowed, the distal end oblique with acicular process 

 at the more projecting dorsal corner. The notopodium is a distinct, well- 

 separated lobe, subcyhndric at the base and distally formed much like the neuro- 

 podium, which arises on the dorsal surface a little distad of the middle of the 

 parapodium. At the base of each non-elytrophorous parapodium there is above, 

 a characteristic, short, distally rounded, subcylindric process. Just proximad of 

 the notopodium is the dorsal cirrus, which from the traces alone left in the type, 

 seems to have been small. The ventral cirri are also lost excepting on a few 

 anterior pairs; on the second metastomial parapodia the cirrus is attached near 

 or a little distad of the middle of the length, and extends clearly distad of the 

 end of the parapodium; on the following pair of parapodia the cirri are shorter 

 and scarcely exceed the neuropodium proper distally, though on one side the 

 cirrus of the third somite is elongated like that of the second; the cirrus is slender 

 with a slight subterminal thickening and a fine terminal filament. 



The acicula are pale, more or less vitreous in appearance. Each projects 

 but moderately beyond its slenderly conical process, very much less exposed 

 than in the preceding form; distally it is very fine and easily bent back into a 

 curl. All setae appear to have been broken off, no complete ones being detected 

 in either of the types. 



Locality. Off Mexico: Sta. 3425 (lat. 21° 19' N., long. 106° 24' W.). 

 Depth, 680 fms. Bottom of green mud and sand. Bottom temp., 39° F. 18 April, 

 1891. Two specimens. 



Characterized especially by the form of the lateral prolongation of the 

 median ceratophore; instead of rising free from the prostomium as in the pre- 

 ceding species, these extend as simple but conspicuous ridge-like elevations out 

 to the bases of the lateral tentacles. The feet are relatively decidedly longer 

 than in hastigerens, each in length much exceeding the width of the somite to 

 which attached. The forms of the notopodial processes and especially of the 

 basal dorsal processes of the interelytrophorous somites are characteristic. 



