1905.] NATURAL SCIENCES OF PHILADELPHIA. 855 



XX. They are small and their number rather large, about 140-150 on 

 V, 116 to 120 on X, about 110 in each series on XX and about 50 to 60 

 on the middle abdominal tori. They have the general form described 

 for other species of the genus (fig. 13). The base is small and oblique, 

 strongly convex below and with a prominent anterior angle, above 

 which is a deep narrow sinus from which a slender process bearing the 

 delicate, scarcely visible guard arises. There is no distinct neck, but 

 a large head with a slender, acute, strongly decurved and slightlj^ re- 

 flected beak, above which is the high, full crest with four cross rows of 

 teeth. 



No color remains. 



The type comes from station 4,194, in the Gulf of Georgia, the depth 

 being 111 fathoms and the bottom of soft green mud. The station 

 from which the second specimen was taken is unknown. 



Laena nuda sp. nov. (Plate XLIV, figs. 14, 15.) 



This is another imperfectly known species, the only specimen 

 available being a fragment of the anterior end measuring 21 mm. 

 long and 1.5 mm. across the thorax, and comprising 28 anterior seg- 

 ments. 



Projecting prominently from the anterior end is a broad, unfolded, 

 scoop-like prostomial membrane curving gently and regularly upward 

 from beside and above the mouth. Apparently the tentacles formed a 

 complete series around the margin of the posterior limb of the pro- 

 stomial membrane, but in this specimen most of them are gone and the 

 three or four remaining are short and thick, and scarcely reach beyond 

 the free border of the anterior prostomial membrane. Behind the ten- 

 tacles the posterior prostomial fold is low and thick and at the dorsum 

 nearly obsolete. On its posterior face are traces of a few eyes. 



The mouth is a large, wide, transverse slit slightly bent down at the 

 margins, and is bounded below by a low thick lip, and a prominent, 

 broad, truncate process with slightly fimbriated margin springing from 

 the middle of the peristomium. 



Anterior somites are irregularly developed, the second being much 

 larger than the adjacent ones. The second to eleventh somites in- 

 clusive have ventral plates, the glandular areas extending upward to 

 include the setse tufts. The third to the seventh have dorsal glandular 

 areas also, which are separated on each side from the setigerous tuber- 

 cles by a narrow non-glandular space. On the eighth also is a trace of 

 a glandular region with a median break. 



Not the slightest trace of gills exists. At the dorsal margin of III, 



