1903.] NATURAL SCIENCES OF PHILADELPHIA. ' 421 



30 mm., and the type 26 mm. long, and 11 wide between the tips of 

 the parapodia. 



Prostomium a flattened spheroid, slightly wider than long, with 

 a shghtly elevated median area which fades away anteriorly and 

 widens posteriorly, where it is continuous with the jDeristomium. 

 Ocular peduncles about f as long as the prostomiimi, from the anterior 

 face of which they arise, the ends enlarged and globular, the iDases nar~ 

 row and stalk-like; no distinct eyes, but a sUght discoloration of the 

 ends of the peduncles. ^Median tentacle with a thick swollen cerato- 

 phore which fills the space betw^een the ocular peduncles, and about 

 equals the prostomium in length; the style excessively slender, fili- 

 form, scarcely tapered, at least 9 times as long as the prostomium, its 

 extremity slightly bulbous, with a subterminal constriction and a 

 second more proximal enlargement. Palpi ver}' slender, regularly 

 tapering, whiplash-like, fully 15 times as long as the prostomium. 

 Facial tubercle prominent, extending from the base of median tentacle 

 into mouth, covered with conspicuous papillae arranged in rows. 



Peristomium short, coalesced with median portion of prostomium 

 above, and united with somites II and III to form a broad quadrate 

 postoral plate below. Setigerous somites 33, very indistinctly limited 

 except at the bases of the parapodia ; the surface quite smooth except 

 on the postoral plate and the region immediately following, which are 

 covered with globular papillae of much smaller size than in many other 

 species. The integuments are extremely transparent, so that the in- 

 ternal organs, and particularly the arrangement of the alimentary 

 canal, nervous system and the masses of germ cells, can be clearly seen. 

 The retracted proboscis reaches to somite XVI. 



Parapodia of the usual form, with only a few very small spherical 

 papillae on the ventral surface; notopodia short, conical, directed 

 nearly vertically on the scale-bearing, horizontally on the cirri-bearing 

 somites ; neuropodia long, very slender, and truncate at the end. Dor- 

 sal cirri of the same form as the median tentacle, equalling or exceeding 

 the width of the body, and reaching far beyond the ends of the setae. 

 Ventral cirri short, about i the length of the neuropodium, slightly 

 tapering, blunt-pointed. Peristomial parapodia directed straight for- 

 ward by the sides of the head, and nearly twice as long as the pro- 

 stomium with its ocular peduncles. At its end a spreading tuft of 

 capillary setae arises from the inner side and occupies the space in front 

 of the head, while from the outer face the tentacular cirri spring at 

 right angles and then curve forward; they have form of the dorsal cirri, 

 but are scarcelv half their length, and much less than the median 



