PODARMUS. 45 



PoDARMus, gen. nov.^ 



Body short, tapering caudad, composed of comparatively few somites. 

 Colorless and transparent. 



Prostomium wider than long, divided by a median furrow. Bearing 

 three tentacles all of which are inserted marginally. Ceratophore distinct, 

 the style smooth and tapering. Palpi long and slender, gradually acuminate. 



Parapodia uniramous, long (typically exceeding in length the width of 

 the somite), at the distal end compressed anterocaudally and divided by a 

 vertical fissure into a presetal lip and a shorter postsetal lip. Notocirrus 

 attached toward base of parapodium above, long. Neurocirri attached distad 

 of middle, short and subulate. A conspicuous cylindrical process extends from 

 the caudal face near the same level as the neurocirrus than which it is much 

 stouter but shorter. 



Only neuropodial setae present, these consisting of stouter ventral ones 

 and but little more elongate though much more slender dorsal ones, the head 

 in these being very much more drawn out. The two forms equal in number 

 or nearly so. Tips entire. No special natatory setae. 



Character oi elytra not known. Elytrophores in type fourteen pairs, 

 occurring on somites II, IV, V, VII and alternate somites to XXIII inclusive 

 and then on XXVI and XXIX. 



Genotype. — P. ploa, sp. nov. 



Apparently this form is mostly closely related to Drieschia Michaelsen, 

 but it differs in possessing the characteristic posterior process on the parapodia 

 and conspicuously in the form and proportions of the setae. In the present 

 form the two types of setae are obviously a modification of the same primary 

 type, and the coarser ventrals are nearly as long as the dorsals and are numerous, 

 being essentially equal in number to the dorsals with which they are not inter- 

 mingled. In Drieschia pelagica Michaelsen, type of that genus, as indicated 

 by Michaelsen's description and figures, the stout setae are proportionately to 

 the dorsals very much shorter, more or less strongly curving sigmoidally, and 

 very much fewer than the fine dorsals, which in turn proportionately to the 

 parapodia are very much longer. 



* TToiis, foot, and apuds, a peg, in reference to the cylindrical process borne on the posterior side of 

 the parapodium. 



