436 PROCEEDINGS OF THE ACADEMY OF [Juiie, 



from which it is imperfectly separated laterally, and only about ^ as 

 long as somite V; tentacular cirri tapering, rather faintly articulated 

 in the terminal half, reaching anteriorly to the cephalic margin of the 

 peristomium and posteriorly to V. Body little depressed, strongly 

 convex even in the branchial region, and with a very strongly marked 

 neural groove. Length of somites, which are very distinct, increases 

 to VI, which is three times as long as II, undergoes httle diminution 

 in the branchial region, but increases somewhat in the region posterior 

 to the principal branchiae. 



Parapodia similar in form and variations to E. mucronata, but the 

 neuropodium rather larger and the whole more prominent. The noto- 

 podial cirri are remarkable for the very large size of the basal portion, 

 which much exceeds the entire neuropodium in size in the middle re- 

 gion of the body. Notopodial cirri relatively short, about twice the 

 length of the neuropodium to which they are attached, scarcely reach- 

 ing half-way to the dorsimeson, tapering, faintly articulated at least 

 anteriorly, the basal sense-organ very small; a conspicuous bilobed 

 brown spot occurs just within the body at the base of the dorsal cirrus. 



Branchiae appear suddenly as two filaments on the left side of IX 

 and 3 on the right side of X, increasing to 4 on XI, 5 on XVIII and 

 XIX, which number is maintained to XXXV and XXXVII, with an 

 occasional variation to 4, especially on the right side, then 4 and 3 to 

 XLI, and 2 for the remainder of the piece. Even when best developed 

 the branchiae of the two sides are separated by fully half the width of 

 the back. Their aspect is very different from the branchiae of E. 

 mucronata; the stem arises in the same way and curves mediad over 

 the back, but it is angulated, and the branches, instead of arising erect, 

 dicotomose nearly regularly with it and curve parallel to it toward the 

 median line. 



The number of setae is moderate, the compound and capillary being 

 about equal and rather definitely arranged in rows. Compound setae 

 very pale yellow, rather stout, the terminal portion of the shaft thick- 

 ened for a distance of 5-6 times the ordinary diameter, with axial stri- 

 ations and marginal denticulations for a long distance ; appendage rela- 

 tively short, less than the enlarged end of shaft, the tip strf)ngly hooked 

 and prominently bifid; the guard broad, extending a short distance 

 beyond tip of appendage, striated and marginally denticulated. 



Capillary setae colorless, gently curved like an italic /, slightly en- 

 larged about middle with a narrow denticulated wing, and tapering 

 to a fine point in the terminal ^. Paddle-shaped pectinate setae wider 

 than in other species of Eunice herein described, with about eleven 



