1911.] NATURAL SCIENCES OF PHILADELPHIA. 309 



latter is somewhat the longer and the former marked by a slight con- 

 striction separating a distal portion corresponding to a much broadened 

 Ungulate process of anterior parapodia. Neurocirrus much shorter 

 than neuropodium and divergent from it. The notopodium consists 

 of a deep postsetal lip broadly attached to the notocirrus above with a 

 slight emargination at the tip of the aciculum, and a small subovate 

 presetal lip or process just ventral to the end of the aciculum. Noto- 

 cirrus shaped much like neurocirrus, but shorter and lacking the basal 

 depression and bending which characterizes anterior notocirri. Toward 

 the caudal end the rami are relatively longer and more divergent. 



Acicula in each ramus single, rather stout, straight, tapering rods 

 ending in blunt points ending flush with the surface, the neuropodial 

 being sometimes slightly bent at the tip. Neuropodial setae in a 

 broad spreading fan-shaped fascicle of one series, divided into nearly 

 equal dorsal and ventral groups by a considerable interval at the 

 aciculum into which the tonguelike prolongation of the presetal lip 

 enters. On the type they are distributed as follows: somite N 16 

 supra-acicular and 14 subacicular, XXV 21 and 22, L 23 and 22, C 

 28 and 24. They are all of one kind, compound, capillary, slender 

 and colorless, the gently curved shafts slightly enlarged at the distal 

 end (fig. 164) to form a bifurcate socket with unequal limbs, the 

 longer of which is faintly toothed. Appendages very delicate, slender, 

 tapered, more or less curved, very finely punctate and along the edge 

 finely fringed. They are shortest at the dorsal and ventral borders 

 of the fascicles and gradually increase in length to acicular borders. 

 Except that they are very long and slender on the middle segments, 

 there is no obvious distinction between these setae on the two regions 

 of the body. Notopodial setae (fig. 165) are few, three supra-acicular 

 on XXX, three supra-acicular and two subacicular on L and four and 

 three, respectively, on C. They are simple, colorless, delicate and very 

 small, with a peculiar knoblike prominence on one side, beyond which 

 they are prolonged into a very slender, acute tip. On more anterior 

 parapodia these tips are exposed, but farther back they are shorter and 

 concealed between the notopodial lips. 



Proboscis, when fully retracted, reaches to somite XLIX, where the 

 jaws lie. None of the specimens has it fully everted. It is most 

 fully so on a cotype (station 4,480) on which it is 8 mm. long and 

 2 mm. in diameter, cylindroid, of uniform diameter, with four broad 

 longitudinal ridges (one dorsal and one ventral pair) bearing four 

 bands of horny papillae or paragnaths. These bands extend for nearly 

 the entire length of the eversible proboscis from the jaws nearly to 



