178 PROCEEDIXGS OF UNITED STATES NATIONAL MUSEUM. 



clavate, inieqnal, branchial cirri, mostly less than four times as long as 

 the diameter of the body. The two anterior segments have slender ca- 

 pillary seta) in the upper fascicles, less long than the diameter of the body; 

 they increase in length and numbers farther back, and on the seventh 

 and forty to fifty succeeding segments they become very numerous and 

 remarkably long, being from two to three times as long as the breadth of 

 the body ; toward the posterior end of the body they again diminish in 

 length, becoming comparatively short on the last twenty segments. The 

 ventral set» are all capillary and fine-pointed on the anterior and median 

 segments ; they somewhat exceed the diameter of the hody in the middle 

 segments, but are shorter toward both ends. On the last twenty seg- 

 ments there are, in each ventral tiiscicle, one or two short unciuiform 

 sette with somewhat hooked but scarcely bidentate tips. Similar unciui- 

 form setoe exist in some of the posterior dorsal fascicles. The setse are 

 silvery white. Body dark olive-green, with lighter dorsal line ; branchiae 

 with dark tips. Length, about 25"^'" 5 diameter, without appendages, l"""^ 

 to 1.7o""". 



Off Campo Bello Island, Bay of Fundy, GO fathoms, burrowing in dead 

 shells of Pecten temiicostatus, 1872. 



Dodecaceria coucharum Oersted. 



This species is nearly allied to the last, and occurred with it. It is 

 very common, on our coast, in various shells. The genus Dodecaceria 

 CErsted has not been distinctly distinguished from Heferocirrm Grube, 

 to which it is closely related. The number of branchial cirri is variable 

 in both, but their arrangement is the same. The seta), however, are 

 different in their arrangement. In D. concliarum the 1st segment bears 

 no seta) ; on the 2d to 7th there are short capillary setffi, above and 

 below ; on the 8th there is a solitary, long, unciniform seta in the dorsal 

 fascicle of capillary setoe, and four or five stouter ones, with bidentate 

 tips in the ventral fascicles, and no capillary ones ; on the Otli and suc- 

 ceedimg segments, the ventral seta) continue as on the 8th, and the 

 dorsal fascicles usually contain four or five elongated, simple, hooked 

 uncini, together with more or less numerous fine, acute, cajnllary set*, 

 which are often absent, but they occur on some of the segments even to 

 the posterior end, where they are often about one-third as long as the 

 diameter of the body. Behind the middle of the body the uncini become 

 smaller, shorter, and fewer, only two or three to a tascicle, but near the 

 posterior end, on four or five segments, they become stouter, more hooked, 

 and distinctly bidentate, especially on the ventral side. 



The color is usually dark green or greenish black, and no distinct 

 ocelli were detected, but some obscure dark specks may represent them. 



Praxillura, geu. iiov. 



Body very long and composed of a larger number of segments than is 

 usual in the MaldankJcv. Posterior segments very numerous, short, be- 

 coming intlistinct posteriorly. Caudal segment subacute, destitute of 



