1906.] NATURAL SCIENCES OF PHILADELPHIA. 353 



bodies of pigment occur with the eyes. The mouth is a minute open- 

 ing situated at the very bottom of the vertical prostomial cleft near the 

 ventral surface. 



The peristomium (a) is but little modified and a segment just like 

 the others, except that the parapodia lack the capillary setae. The 

 sides of the body are nearly parallel almost to the caudal end, where the 

 last 12 to 15 of the total number of 40 to 43 segments taper to the 

 pygidium. Each segment is about ^ as long as wide, or anteriorly 

 rather more than this. The small triangular pygidium bears a pair 

 of large, stout moniliform cirri of about 25 joints, and in the males an 

 additional short, slender, and un jointed median ventral cirrus. 



Excepting the first pair the parapodia (b) are biramous, and all but 

 the first and the last few bear capillary setse in the notopodium. The 

 basal part is a rather large dome-shaped structure, from which the 

 neuropodium projects rather prominently and ends in a short, slightly 

 curved dorsal acicular process, while a postsetal lamina, stepped at the 

 ends for the rows of setae, forms its more ventral portion. Two or 

 three straight aciculi support the neuropodium. From the middle of 

 the ventral surface of the foot arises a short, slender, tapered and un- 

 jointed ventral cirrus. The notopodium is a very slight, conical tu- 

 bercle which receives the end of a single aciculum strongly curved at the 

 tip and caps a large yellowish setigerous sac, from which the capillary 

 setae spring. Well above and separated from this tubercle arises the 

 dorsal cirrus, which is always prominent and strongly moniliform. 

 With considerable regularity the dorsal cirri are alternately longer and 

 shorter, the even numbers being about equal to f of the width of the 

 body exclusive of the parapodia and consisting of 20 to 25 joints, 

 whereas the odd numbers are about f as long as they and have only 14 

 to 16 joints. 



As stated above, all but the peristomium and the last 5 or 6 segments 

 bear capillary notopodial setae which form dense and very conspicuous 

 bundles. They are perfectly smooth and simple in structure, glass- 

 like in appearance, tapered to excessively fine but apparently flattened 

 ends, and are more or less curved and sometimes curled and twisted at 

 the ends — the latter condition being probably the result of preserva- 

 tion. 



Neuropodial setae are arranged in 5 or 6 horizontal sub-acicular rows. 

 They are relatively short and stout and perfectly colorless and vitreous. 

 The curved stems are deeply cupped, and toothed along the more pro- 

 longed side. The blades end in a single, rather stout, little hooked 

 tooth, and the dorsal or shorter side is provided with a moderately 



