510 MEMOIRS OP THE UNIVERSITY OP CALIPORNIA 



A few feeble strokes with an extension of the tip only a little beyond the body 

 were repeated from time to time. There was other evidence of a moribimd 

 condition. These observations suggest that the tentacle is small and less active 

 in this species than in many others of the genus. 



Comparisons. — This species belongs to the subgenus Polyopsidella because 

 of its coiupound ocellus, but is most like the subgenus Erijtliropsis in that its 

 compounding is least marked, being shown l)y three sulxlivisions of the lens and 

 slight Iol)iug of this pigment mass. 



It is the only species with compound ocellus and also an apical horn. Its 

 paracingular grooves and beads are more marked than usual in the genus. Its 

 small, uniform, croAvded peripheral vacuoles resemble those of E. cochlea, but 

 are not a])X3ressed into polygonal fields as in that species. Its tentacle when 

 extended resembles that of E. cornnta (Schiitt), but its proportions, ocellus, 

 girdle, and apical horn are quite different from those of that species. 



Erythropsis scarlatina sp. nov. 



Plate 12, figure 128; text figures RR, 2 ; SS, 4 



Diagnosis. — Large species; body elongated subcylindrical ; its length 1.7 

 ti'ansdiameters ; epicone reduced; its diameter 0.5 transdiameter : no apical 

 horn ; sides furrowed ; girdle displaced distally beyond the middle ; tentacular 

 recess oblique; prod sinuous tapering; directed obliquely ventrally; no stylet; 

 ocellus compound; lens of five segments in a row; black-pigment mass lobed; 

 body extensively streaked and mottled with scarlet. Length, 104/^. Pacific off 

 La Jolla, California, August. 



Description. — This species is unique in form, structure, and color. The body is elongate 

 subcylindrical, somewhat truncate at both ends. Its length is 1.7 transdiameters and its dorso- 

 ventral diameter is slightly greater than the transdiameter. The epicone is reduced to an apical 

 button whose diameter is only 0..5 transdiameter and altitude only 0.07, except in the distal 

 quadrant in which it forms a long triangular process extending posteriorly along the right side 

 of the sulcus for a full transdiameter from the apex. The center of the epicone is filled with a 

 lone, rounded terminal knob which probably represents the apical horn. The hypocone forms 

 over 0.9 of the body, its length at the anterior flagellar pore being 0.9 of the total length. 

 Anteriorly its shoulders are rounded in abruptly to the girdle, about twice as far on the right 

 as on its left side. The left margin is quite regularly convex while the right and dorsal are 

 straight or even somewhat concave. The antapex is truncate, its outline being somewhat sinuous 

 as a i-esult of the posterior terminations of the lateral furrows. The sides of the hypocone are 

 deeply scored by parallel grooves which run from the anterior .shoulders to the postmargins. 

 There are five of these on either side of hypocone. They are about equidistant and are deepest 

 near the middle of the body. 



The girdle forms a flat spiral around the button-like epicone with little deflection in its 

 proximal 0.75. At the beginning of the distal quadrant it turns posteriorly at an angle of 45°, 

 and steepens to 15° from the vertical near its distal end which is in consequence carried poster- 

 iorly to the middle of the body with a total displacement of 0.7 transdiameter. The furrow is 

 very narrow, only about 0.05 transdiameter wide, and lies in the hollow of a deep depression. 



