1923] NATURAL SCIENCES OF PHILADELPHIA 207 



Amphicteis glabra Mooro. 



Five specimens of this species. One large example has seventeen 

 or eighteen paleoli; the others are normal in this and generally in 

 other respects. Except on one in which they are often six-toothed, 

 the uncini are always five-toothed. The anal cirri are long as in 

 A. mucronata. 



Stations 4452, oft" Point Pinos Lighthouse, 49-50 fathoms, green 

 mud, fine sand; 4526, same locality, 204 239 fathoms, soft gray 

 mud. 

 Amphicteis sp? 



Two small, poorly-preserved specimens, lacking all gills, resemble 

 A. scaphobranchiata in the number and form of the paleoli and the 

 number of uncinial teeth. The thoracic uncini, however, are much 

 less produced above and the prostomium is truncate and entire 

 and not produced and tri-lobed. In both of these respects it 

 approaches Ampharete and differs from typical Amphicteis. 



Stations 4453, off Point Pinos Lighthouse, 49-51 fathoms, dark 

 green mud; 4508, same locality, 292-356 fathoms, soft green mud. 

 /Image arieticornuta sp. nov. Plate XVII, figs. 14-18. 



Prostomium coalesced with peristomium, firm and rigid, trilobate, 

 consisting of a quadrate, petalliform median plate and a pair of 

 flaring lateral lobes; median plate broader than long, widest at 

 anterior border, saddle-shaped, being strongly concave antero- 

 posteriorly and convex transversely, anterior liorder strongly 

 flaring dorsad, with a truncate anterior fac(^; lat(M-al lobes strongly 

 marked, with convex borders, somewhat tumid, rigid. On each 

 side a shallow furrow runs caudad from the incision between the 

 median and lateral lobes. Extending transversely across the 

 median plate and uniting with the lateral lo]>es at the sides is a 

 broad annulus, the free anterior border of which forms a low trans- 

 versely concave nuchal fold, the lateral portions of which conceal 

 the nuchal sensory slits and almost conceal the low pads anterior to 

 them. A soft median pai)illa is visible in some specimens above the 

 mouth and nearly concealed by the base of the i)r()st()niial ]ilate. 

 No eyes. Tentacular mem])rane concealed. Tentacles moderately 

 numerous, very short, smooth, scarcely visible beneath tiie prosto- 

 mium. 



Peristomium contracted dor.sally but vent rally forming a broad 

 thick, stiff", much furrowed, projecting 1ow(t lip, i)roduced laterally 

 into a pair of auriculate wings. 



Somite II a well-developed simple ring dorsallj^ a short, rounded 

 glandular ridge ventrally. Ill is a much larger segment with a 

 thick glandular plate below, prominenlh' ))r()j('cting lateral masses 



