462 GASTROPODA. [Pectinibranchia. 



B. Shell without sculpture ; growth-lines only. 



a. Height of spire one- quarter to one-third that of the aper- 

 ture ; shell volutiform ; 4 mm. by 5 mm. to 7 mm. . . pygmcea. 

 an. Height of spire about half that of the aperture. 



b. Outer lip faintly crenate inside ; 3 whorls ; body-whorl 



somewhat swollen above ; 2-4 mm. by 4-2 mm. . . amoena. 

 bb. Outer lip smooth inside. 



c. Shell moderately large, height about 13 mm. ; 

 suture lightly margined ; 5 whorls, sometimes 

 with irregular plications at the suture ; 7-5 mm. 

 by 13 mm. . . . . . . . . muscaria. 



cc. Shell small, height about 3 mm. to 4 mm. 



d. Suture submargined ; spire-whorls rounded ; 



4 whorls ; 2-1 mm. by 3-8 mm. . . hebescens. 



dd. Suture simple ; spire-whorls flat ; 3 whorls ; 



1-5 mm. by 3 mm. . . . . . . lurida. 



6. Marginella amoena, Suter, 1908. Plate 20, fig. 14. 



Marginella (Glabella) amoena, Suter, P. Mai. S., viii, 1908, 184, pi. 7, f. 15. 



Shell small, ovate, rather solid, smooth and polished, with a mode- 

 rately raised spire, white. There is no sculpture. Colour white ; 

 fresh shells vitreous. Spire conoidal, with a blunt apex, a little less 

 than half the height of the aperture ; outlines straight. Protoconch 

 very small, broadly rounded. Whorls 3 ; the spire-whorls flat ; body- 

 whorl large, convex, somewhat inflated above, narrowed towards the 

 base. Suture indistinct, not impressed. Aperture slightly oblique, 

 high and narrow, the margins subparallel, lightly channelled above, 

 truncated and not notched below. Outer lip somewhat convex, 

 thickened, the inner margin faintly and minutely crenate, with an 

 outer varix which does not extend much upon the spire, slightly 

 sinuate above. Columella oblique, straight, with 4 nearly equidistant 

 strong plaits, the upper two almost transverse, the lower two more 

 oblique, the lowest extending to the basal margin. Inner lip thin and 

 transparent. 



Diameter, 2-4 mm. ; height, 4-2 mm. 



Animal unknown. 



Type in my collection. 



Hob. Near the Snares, in 50 fathoms (Captain Bollons). 



Remark. - - This species is very nearly allied to M. hebescens, 

 M. & S., but is distinguished from it in being a little larger and more 

 ventricose, having the spire slightly lower and broader, the spire- 

 whorls flat, the protoconch much smaller, the suture not impressed, 

 and the outer lip minutely crenate. 



7. Marginella hebescens, Murdoch and Suter, 1906. Plate 20, 



fig. 15. 



Marginella hebescens, M. & S., T. N.Z.I., xxxviii, 1905 (1906), 290, pi. 23, 

 f. 25, 26. 



Shell small, moderately solid, suboval, smooth and polished. The 

 sculpture, consists of irregular minute and smooth growth-periods. 

 Colour white or pale-creamy, pellucid when fresh. Spire elevated 



