1903.] NATURAL SCIENCES OF PHILADELPHIA. 797 



slender, the other short and stout, but both are essentially of the type 

 found in the neiu'opodium of Lepidonoius and its allies, though the 

 slender ones superficially resemble the notopodial form. Both kinds 

 are colorless and vitreous. The former kind (fig. 7) are arranged in 

 a spreading fan-shaped fascicle, and manj^ of them are exceedingly 

 long and slender, their total length equaling or exceeding the entire 

 transverse distance between the tips of the parapodia. A^ery fre- 

 quently the inner ends of those of the two sides of the body touch or 

 even overlap in the ccclom beneath the intestine, and their protruded 

 portions reach beyond the parapodia to a distance equal to or even 

 twice its length. For the greater part of their length they are smooth 

 and of an even diameter, but at a point on the exposed part a variable 

 distance from the end a more or less distinct enlargement occurs, 

 beyond which the seta tapers very gradually into a fine, usually 

 slightly curved tip, the convex margin of which is marked by a series 

 of minute appressed scales. The length of this tip varies greatly even 

 in setae which are contiguous in the bundle. The shortest setae of 

 this kind occm- in the ventral portion of the anterior bundles and the 

 longest in the middle portion of the posterior bundles. The number 

 is greatest in the middle somites and diminishes each way, the last 

 parapodium having but one in this specimen. 



The stout setae (figs. 9 to 12) recall the form of those of Scalesdosus. 

 They are 2 or 3 times as thick as the slender ones and very much 

 shorter. Near the end is a rather abrupt enlargement, beyond which 

 they taper somewhat irregularly into a short, somewhat hooked tip pro- 

 vided in newly formed setae with a flexible appendage, which in most 

 instances is quickly worn away. On the dorsal side of the thickening 

 is a short transverse fringe, followed along the same or concave side 

 of the tip by 4 or 5 pairs of delicate combs reaching about half-way to 

 the tip. Almost invariably 3 stout setae are found in the ventral part 

 of the parapodium, and the dorsalmost one only is accompanied by a 

 slender seta. On the first parapodium (II) are a few setae of an inter- 

 mediate type (fig. 8); the vcntralmost one is the stoutest, the dorsal 

 one most attenuated. The two kinds are well difTerentiatcd on III. 



The alimentary canal is slender and thin-walled, with regvilar enlarge- 

 ments at the septa. A few degenerating ova in the ccelom establish the 

 sex. As indicated above the specimen is colorless and pellucid, with 

 distinct pigment in the eyes only. 



The only known specimen was taken in the surface tow-net, 70 miles 

 southeast of Nomans Land, Massachusetts, on the border of the Gulf 

 Stream, on July 31, 1902, along with Salpae, several species of pteropods 



