PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 175 



parapodia, above and below, bear slender, very acute, bent setae, and a 

 prominent, flat process, somewhat expanded and rounded at the end; 

 on the first segment, these are smaller and less spatulate, and the sette 

 are fewer and shorter. The fifth segment is about as long as the three 

 preceding ones, not much swollen, and it bears three distinct groups of 

 setsB, differing in form ; the upper and most anterior are fine, bent, capil- 

 lary setae, with acute tips, similar to, but much smaller than, those of the 

 preceding segments; below these there is a group of small, slender setse, 

 abruptly bent backward and with blunt tips; then there is a row of 

 five or six large, strong, dark-colored, nearly straight, blunt spines, 

 which are nearly equal in diameter, the anterior and upper ones longer, 

 and, when projected at right angles to the body, forming an oblique, 

 somewhat curved, transverse row; finally, in a row below the last of 

 these, are two or three lighter-colored and more slender, straight spines, 

 with abruptly tapered, acute tips. On the succeeding segments, the 

 lower fascicles consist of strong, elongated uncini, in rows of six or 

 seven, with the tip bidentate, strongly curved, beak-like, and with a thin, 

 spatulate border; near the posterior end, they are replaced by acute 

 setiB and fine capillary ones. The upper fascicles, on the segments be- 

 hind the fifth, consist of numerous, long, bent, very acute setre, like 

 those of the anterior segments, the upper one in each fascicle with longer 

 and more slender tips than the lower ; toward the posterior end they 

 become longer and fewer, with straighter tii)S, equalling or exceeding 

 the diameter of the segments. Branchiae appear in a rudimentary form 

 as small papillae on the sixth segment; on the seventh they are short 

 conical papillae ; on the eighth they become longer and more distinctly 

 ligulate, and increase in length on the following segments, soon becom- 

 ing long and slender, recurved, and meeting across the back. They 

 exist on one hundred or more of the succeeding segments. After the 

 branchiae cease the succeeding segments are very numerous, smaller, 

 and rounder, so that the body is more slender and attenuated poste- 

 riorly, and somewhat broader and a little flattened on the branchiferous 

 portion. Anal segment small, terminating in four small, roundish, 

 equal, flattened lobes. 



Color somewhat variable, usually pale flesh-color, or grayish or yel- 

 lowish white anteriorly, and more or less tinged with dull greenish or 

 brownish posteriorly, the red dorsal vessel showing plainly, and the 

 branchiae red. Length, 100™™ to 140™™; breadth, 1™™ to 1.5™™; length of 

 antennae, 20™™ to 30™™. Described from life. 



Very common all along the coast, from Cape Cod to ^N'ova Scotia, in 

 10 to 100 fathoms, in tortuous, narrow galleries excavated in shells, 

 especially of Cyprina Islandica ; also in decayed wood dredged in 32 

 fathoms off Cape Cod. Collected by the writer in the Bay of Fundy in 

 18G3, 1864, 1868, 1870, and subsequently at various localities while dredg- 



