1903.] NATURAL SCIENCES OF PHILADELPHIA. 449 



reaches the level of the anterior margin of the head, and the second 

 as far as the base of the median tentacle, the total length of the second 

 being somewhat greater. Each is svibcylindrical, about 3 times as 

 long as thick, truncate, with short presetal and postsetal lobes, the 

 latter somewhat longer and deeper, and a small papilla-like lobe on 

 the ventro-distal angle. Dorsal cirri arise from the middle of the 

 dorsal surface by a slightly constricted base and then bend outward 

 and extend stiffly nearly parallel to the neuropodium or even approach 

 it and reach somewhat beyond its tip. Ventral cirri also arise by a 

 constricted pigmented base, beyond which they have the form of a 

 spruce cone and extend toward the middle ventral line, which they 

 nearly reach owing to the approximation of the parapodia; the first 

 arises nearly opposite to the dorsal cirrus, the second near the base 

 of the foot. 



The third and all succeeding parapodia are lateral in position and 

 gradually attain a higher plane; they are smaller and project straight 

 outward. On the third the neuropodial cirrus is much shorter, broad 

 oval in outline, and on succeeding parapodia becomes a mere opacjue 

 rounded lobe, which gradually becomes less and less prominent and 

 disappears at about XXX. 



The tenth foot is typical. It consists of a short trimcate neuro- 

 podium with a small presetal lobe, a tapering bent notopodial cirrus of 

 about twice its length, and the reduced neuropodial cirrus. The pos- 

 terior parapodia are further reduced, but, owing to the very poor 

 preservation of this region, cannot be accurately described. 



Branchiae appear on somite X as a single thick filament rising from 

 the dorsal side of the notopodial cirrus; the brancliia is double the 

 length of the cirrus in succeeding somites, becoming bifid on XXIII 

 and thence backward rising erect as two equal divisions twice as long 

 as the cirrus. The posterior end is much macerated, but on the last 

 12 or 15 somites the branchiae appear to consist of single filaments of 

 undiminished length. 



On a very large number of parapodia the setae are destroyed, but 

 enough remain to permit the description of their general character 

 and distribution. The first tw^o enlarged parapodia each bear 3 large 

 setae or acicula, but unfortunately the tips of all have been broken 

 off. Succeeding somites exhibit compound, capillary and paddle- 

 shaped setae, all of which are colorless. 



Compound setae of two forms, the first of which appears to be con- 

 fined to a group of about half-a-dozen in the ventral part of the third 

 parapodium ; they have the end of the shaft rather abruptly enlarged 

 29 



