1923] NATURAL SCIENCES OF PHILADELPHIA 191 



and channels containing hundreds of the more or less mutilated 

 worms. 



Station 4496, off Santa Cruz Island, 10 fathoms, fine gray sand 

 and rocks; 4502, same locality, 9-11 fathoms, hard sand. 



TEREBELLIDAE 

 Artacama conifera Moore. 



Of sixteen examples of this species only one (Sta. 4522) is complete 

 with twenty thoracic and sixty-three abdominal segments and 

 measures sixtj'-eight mm. in length. The pygidium is a rugous 

 ring equal in diameter to those which precede it and ])earing a few 

 small papillae but no cirri. Several have the proboscis exserted. 

 It consists of a rugous basal ring and a slender cone thickly studded 

 with small papilla^. 



Station 4485, off Santa Cruz Island, 39-108 fathoms, soft green 

 mud; 4510, off Point Pinos Lighthouse, 91-184 fathoms, gray mud; 

 4522, same locality, 130-149 fathoms, gray sand and shells; 4523, 

 same locality, 75-108 fathoms, soft, dark mud. 



Leaena gracilis sp. nov. Plate XVII, fig. 8. 



The ty])e and only known specimen is a well-preserved, slender 

 and nearly complete worm measuring 38' mm. long by 1.2 mm. in 

 diameter and consisting of 44 segments, 18 of which are thoracic. 

 Seta? begin in IV, uncini on V. 



Prostomium a thick, prominent, arched biloV)ed plate bearing 

 about a dozen tentacles, the longest about twice the maximum 

 diameter of the body; others have become detached. ]\Iouth small, 

 largely overarched by the prostomium and bounded ventrally by 

 the peristomium. 



Peristomium nearly twice as long dorsally as ventrally, forming 

 above a low fold projecting over prostomium, and below a smooth 

 lip divided into two rings by a transverse furrow. Somite II is 

 less than one-half and III less than two-thirds the dorsal length of 

 I, both with thick lateral prostomial projections, otherwise quite 

 smooth and simple. IV is precisely similar exce])t that the tlorsal- 

 most and most prominent part of the parapodial projection ])ears 

 a small tuft of setae. A very minute tubercle or vestigial cirrus 

 occurs on III above the level of the parapodiuni. 'I'licre is no trace 

 whatever of gills. 



Remainder of body of nearly uniform diameter, tapering very 

 gently. Thoracic segments not indicated by furrows but only by 

 the parapodia and ventral plates; they increase in length very 

 slowly to XI and l)ehind that more rapidly, the posterior thoracic 

 and anterior a])dominal l:)eing each about two-thirds as wide as 

 long. With the exception of the first two or three, abdominal 



