1923] NATURAL SCIENCES OF PHILADELPHIA 251 



coming so long as to almost ecjual the width of the body. Uncini 

 are almost sessile, the tori being scarcely elevated. On the thorax 

 these are 20-25 and on the abdomen about half as many in each 

 series. As usual in the genus they are small, triangular plates with 

 numerous fine marginal teeth arranged in three or four rows of 

 about eight or nine teeth each. 



Tubes white, delicate, calcareous, not more than .4 mm. in 

 diameter, slightly roughened by growth lines but otherwise of 

 simple structure. They form coherent groups side by side and 

 taking slightly tortuous courses in which particular tubes will 

 attach to and separate from small clusters, the result being the 

 formation of an irregularly reticulated mass. 



Worms for description were extracted from the tubes by solution 

 in acid and consequently was so indifferently preserved that a 

 full account is impossible. 



Known from one small mass of tubes only from Station 4431 

 off Santa Rosa Island, 38-45 fathoms, mud, sand and rocks. 



Metavermilia multiannulata sp. nov. Plate XVIII, flg. 48 



Described from the type, which is a complete specimen filled 

 with small ova removed from a portion of tube. Length 24 mm., 

 (gills 4.5 mm., thorax 3.2) maximum width 1 mm. Segments 

 about 72, thorax seven setigerous, six uncinigerous, abdomen 

 about 64, the last few indistinct. 



Operculum 3 mm. long, 1.3 mm. in diameter, projecting 4.2 

 mm. beyond end of gills; base egg-shaped, white and soft, pro- 

 longed distally into a slender, brown conical tip (shaped like a 

 fool's cap) a})out three times as long as the white base and marked 

 by fourteen slighth' raised annular lines spaced nearly regularly, 

 the last at the slightly truncate tip. A faint annular furrow marks 

 the junction of base and cap. The operculum is not quite radially 

 symmetrical, being more convex and swollen ventrad and slightly 

 flattened dorsad. Opercular stalk, which is the left dorsalmost 

 branchial radiole, slightly depressed, enlarged at both ends, the 

 narrow part in the middle region of a diameter about twice the 

 other radioles. It has a peculiarly twisted appearance, being marked 

 by raised strands separated by furrows, nearly transverse at the 

 base but spiral elsewhere, much like a piece of rope. At the point 

 of attachment of the operculum to the stalk is a slight furrow. 



Gills 14 pairs, closely wra])i)ed round the ojiercular stalk or 

 radiole and fitted to the base of the oi)erculum, together forming 

 a cylindrical plug equal in diameter to the <)])er('uluin and witli 

 it closely filling the mouth of the tube. Bases or branciiiophores 

 simple, not produced ventrally. Hadioles thick, coarse, and brittle, 

 appearing as though swollen, slightly inroUed on the dorsal, not 

 the ventral, side and each ending in a naked, flattened ti]i having 



