248 PROCEEDINGS OF THE ACADEMY OF [April, 



have well-differentiated shoulder, neck and head. The latter (fig. 

 42) bears a stout, strongly hooked beak, above which are four stout 

 profile teeth of diminishing size, flanked by a few small lateral teeth. 

 The guard arises well below the beak and consists of about twelve 

 coarse fibres which spread in front of and above the apex of the latter. 

 The internal fibrous structure is strongly developed. 



Several tubes of this species occur in the collection and are interest- 

 ing in structure. They measure 70 to 80 mm. long and 2.5 mm. in 

 diameter, and occur either singly or attached in groups or to foreign 

 bodies. Their walls are thin but hard and very brittle and are com- 

 posed chiefly of small sand grains and sponge spicules, the latter of 

 which are so attached that their pointed ends project freely toward 

 the mouth of the tube. Various kinds of foraminifera and other 

 foreign bodies are attached to the tubes, which are always dark- 

 colored at the distal end and clean and pale elsewhere. 



Two complete worms and a fragment together with four or five tubes 

 were taken at Station 4,264, off Freshwater Bay, Chatham Strait, 282 

 to 293 fathoms, bottom of green mud. 

 Sabellaria cementarium sp. nov. Plate XII, figs. 45-51. 



The fine species which represents the genus Sahellaria along the 

 Pacific coast from Washington to Alaska is represented by a number of 

 specimens, but unfortunately only one of these is complete, the others 

 having lost the posterior end either through an attempt to remove the 

 living worm from their tubes or by maceration in the tubes. 



The type and only perfect specimen is 81 mm. long, of which the 

 very slender fecal tube contributes 28 mm. The operculum has a 

 diameter of 4.5 mm., the thorax a width of 6 mm., from which thick- 

 ness the abdomen tapers regularly to about 2 mm. at the posterior 

 end and then suddenly contracts to the 1 to 1.5 mm. of the fecal tube. 

 Counting the peristomium there are five thoracic segments exhibit- 

 ing three distinct types of setation, then follow forty ordinary ab- 

 dominal segments and about forty-six segments in the reduced fecal 

 tube; finally the pygidium is a tubular structure 1.5 mm. long and .6 

 mm. in diameter with its posterior end serrate with about twenty 

 minute teeth. 



The prostomium is minute and completely concealed beneath the 

 enormously developed peristomium. The small slit-like mouth is 

 enclosed between a pair of closely appressed longitudinal folds, 

 bovmded laterally and somewhat enfolded ventrally by the enlarged 

 palps, which are completely connate with the peristomium. 



The peristomium is greatly enlarged and in the type measures 6.5 



