242 PROCEEDINGS OF THE ACADEMY OF [April, 



also has by far the most prominent beak. On the remaining somites 

 the uncini differ decidedly in the form of the head (fig. 35) which is 

 much enlarged backward. The smaller beak is more curved and 

 hooked, the crest high and prominent, with five or sometimes six non- 

 fibrous, imbricated teeth of diminishing size. The guard consists of 

 several (about 8) fine tapering hairs, which arise from a plate just 

 beneath the beak, the inferior outline of which they follow to the tip, 

 above which the}^ then rise as curled inarched filaments. 



The alcoholic specimen is colorless, but the greatly developed para- 

 podial plexuses of bloodvessels indicate red bands during life. 



Some fragments of tubes are 3 mm. in diameter. Their flexible 

 walls are composed of a soft mucoid membrane covered with a thin 

 coating of very fine neatly deposited sand. 



This species presents interesting resemblances to Praxilla gracilis 

 (Sars) Malmgren in the form of the head and tentaculiform palpode, 

 to Clymenella catenata (Malmgren) in the number of achsetous preanal 

 somites, and to C. ruhrocincta Johnson in the elongated median ventral 

 pygidial cirrus. 



It is known only from Station 4,264, off Freshwater Bay, Chatham 

 Strait, July 25, 1903, 282 to 293 fathoms, bottom of green mud. 



Uicomache carinata sp. nov. Plate XI, figs 36-39, and Plate XII, figs. 43 and 44. 



A well-preserved but somewhat contracted specimen (the type) is 

 65 mm. long and 3 mm. in diameter at the thickest part. Another in- 

 complete but more fully extended example must have exceeded twice 

 this length when complete. 



The prostomium and peristomium are coalesced, forming a continu- 

 ous head about If times as long as wide. The prostomial region is 

 nearly vertical with about its medial ^ formed by a ridge, which forms 

 a prominent profile, somewhat arched above and ending below and 

 anteriorly in a transverse crescent, separated by a slight groove from 

 the short, somewhat thickened palpode. The latter is continuous 

 with the similarly thickened lateral margins of the head, within which 

 is a pair of shallow longitudinal depressions, while within these again 

 and close to the median ridge are the distinct longitudinal sensory slits 

 or nuchal organs. 



The dorsal peristomial region is somewhat tumid anteriorly, with a 

 nearly straight profile posteriorly, but strongly arched transversely 

 throughout. From the prostomium it is slightly distinguished by a 

 faint transverse groove which passes laterally into the depression men- 

 tioned above and the groove which continues the latter posteriorly to 

 the end of this segment. The mouth is a large elliptical opening sur- 



