1923] NATURAL SCIENCES OF PHILADELPHIA 203 



from fourteen to seventeen paleoli in each fascicle. The anterior 

 median gill is always scaphiforni with a slender distal appendage 

 which is sharply hooked at the end, except in a single case in which 

 it is straight. The larger specimens have the marginal lobation 

 of this gill more pronounced and the tip more prolonged than the 

 types. The original description fails to mention the membraneous 

 wing borne on the distal end of the setigerous tu])ercles ventral 

 to the seta? tufts. The uncini have six teeth with occasionally 

 a small, inferior seventh. 



Stations 4322, off Point La JoUa, 193 227 fathoms, soft green 

 mud; 4325, same locality, 191 292 fathoms, green mud and fine 

 sand; 4358, off Point Loma Lighthouse, 167-191 fathoms, green 

 mud; 4364, same locality, 101-129 fathoms, green mud; 4400, 

 lat. 32° 50' 20" N. long. 118° 03' 30" W., 500-507 fathoms, green 

 mud; 4425, off San Nicolas Island, 1084-1100 fathoms, green mud 

 and fine sand; 4433, off Santa Rosa Island, 243-265 fathoms, green 

 mud; 4461, off Point Pinos Lighthouse, 285-357 fathoms, green 

 mud; 4462, same locality, 161-265 fathoms, green mud; 4464, 

 same locality, 36-51 fathoms, soft dark gray mud; 4467, off Santa 

 Cruz Lighthouse, 51-54 fathoms, soft dark-green mud; 4482, same 

 locality, 43-44 fathoms, soft green mud. 



Amphicteis mucronata sp. nov. 



This species is characterized especially by the prolonged terminal 

 mucrons of the paleoli and the large size of the branchia\ 



Form moderately slender for the genus, regularly tapered caudad, 

 subterete, the ventral parts forming a })roader, flattened, sole- 

 like expansion upon which the smooth, domed, dorsal part rests. 

 Segments, counting the paleolar as III, thoracic 20 (17 setigerous), 

 abdominal 15 uncinigerous. 



Cephalic region l^roadly truncate, sul)-conical, somewhat de- 

 pressed and slightly longer than width at the posterior border 

 which exceeds that of the anterior. Prostomium not clearly 

 distinguished from peristomium, its anterior part depressed, 

 consisting of an oblong median cephalic plate 1^-2 times as long 

 as broad, divided by a median longitudinal furrow into a pair of 

 low, rounded ridges, each ending anteriorly in a slightly free, 

 projecting, roundcnl lol)e (palps?) and which are sometimes more 

 ])rominent and unite ventrally into a wedge-shaped thickening 

 (palpode) extejiding to the mouth. Lateral lobes about ecjual in 

 size and similar to median ])late l)ut quite simple and plain in struc- 

 ture, with anterior and lateral l)orders free. Ocular ridges usually 

 high and prominent (l)ut sometimes low) rounded, transverse, 



