1910.] ' NATURAL SCIENCES OF PHILADELPHIA. 369 



description of P. longipedata. Ceratoijiiores of lateral tentacles 

 cylindrical, continuous with the sides of the cephalic face of the pros- 

 tomium and separated by about their own diameter or more, their 

 length about one-fourth of prostomium, j^rojecting straight forward; 

 styles three times length of prostomium without ceratophores. Palps 

 very large, stout at base where they very nearly equal width of pros- 

 tomium, length about six times prostomium, tapered to rather blunt 

 tips lacking a terminal filament; surface smooth and without raised 

 lines or sensor}' cilia. 



Perlstomium little developed, concealed largely by prostomium, its 

 parapodia with large ceratophores and apparently achsetous. Styles 

 of tentacular cirri long, slender, and regularly tapered, the dorsal as 

 long as the palps, the ventral slightly shorter (Pi. XXXI, fig. 59). Body 

 generally subfusiform. Anterior segments narrow, those following 

 widening to middle of piece and decided^ depressed (partly the result 

 of injury), then tapering again to caudal end which terminates in a 

 small pygidium with dorsal anus from w^hich the cirri have been lost. 

 Segments fairly well differentiated, smooth dorsally, the venter with 

 neural furrow and prominent neural ridge. Nephridial papillae 

 (PI. XXXI, fig. 60) very remarkable. They begin on VI, arising in the 

 usual position at the posterior base of the foot and directed dorsad 

 into the interpodal cleft. At first they are delicate and not longer 

 than the diameter of the foot but they rapidly increase in length until 

 at XIV they reach the end of the neuropodium and on following 

 segments extend considerably beyond it as far as the tip of its long 

 acicular process. They are very slender, tapering at the base and 

 filiform for most of [their length. Posteriorly they become again 

 shorter. Just how these long papillae are disposed in the living worm 

 is uncertain but several occupy the position shown by the dotted lines 

 in the figure, passing between the parapodia and hi a groove along 

 the posterior face of the one to which they belong to end at the base of 

 the fascicle of neuropodial setae. Probably this is the normal position 

 but a larger number and especially some longer than the one figured 

 rise, as shown by the solid lines, like doi-sal cirri above the parapodia 

 and back. El)i;rophores and doi"sal tubercles of moderate size but 

 most of them abnormally inflated, precluding an accvu-ate description ; 

 the former situated on II, IV, V and alternate segments to XXIII, 

 then on XXVI and XXVIII = 14. Owing to the mutilation of the 

 specimen this distribution cannot ))e affirmed with entire certainty 

 and it is probable that a fifteenth pair of small ones may exist on the 

 reduced segments at the caudal end. 



