RETUSA. 219 



rounded ; the edge line is convex, and retreats very rapidly in front, 

 where the shell is abruptly truncate. Top very bluntly rounded, 

 the apex being to some extent enveloped in the succeeding whorl, 

 which rises slightly above it. Inner lip: a thick pad of glaze, with 

 well-defined edge, extends down the slightly convex body, and 

 passes with gradual sweep into the twisted subconcave pillar which 

 is truncate in front; at the top of the pillar the glaze is much thick- 

 ened, and presents for a short distance two very oblique twisted 

 parallel folds, which are parted by a small furrow; another furrow 

 lies outside, between the exterior fold and the glaze edge. Alt. 0'3 

 in. diam. 014. Mouth, height 0-25, breadth 003 inch. ( Wats.). 



North of Culebra 1., W. Indies, 390 fms. 



Utriculus spatha W ATS., J . L. S. L. xvii, p. 333; Chall. Rep. 

 Gastr. p. 649, pi. 48, f. 7. 



This exceedingly peculiar form in many respects recalls, rather 

 than a Utriculus, one of the long narrow low-spired Marginellas, 

 such as Marginella nevillii Jouss., or Margin ella avena Kien. 

 ( Wats.). 



R. MAYOi Dall. 



Shell solid, white, with a yellowish polished epidermis and well 

 marked lines of growth, spiral strise very faint and few, or none ; 

 whorls 32-4, spire distinct, little elevated, nucleus small, rounded, 

 not prominent, aperture long, rather wide and straight, the posterior 

 commissure rounded, the anterior wide, the margin spirally curved 

 showing the axis (though this is not pervious) ; umbilical-chink 

 none, pillar broad, white, oblique without any trace of a plication ; 

 outer lip thin, arched forward in the middle ; suture very deep ; 

 inner lip with a wash of callus. Lon. of shell, 8'3 ; of aperture, 

 7-0 ; max. lat. 4-6 mill. (Dall). 



Portland, Maine, from fish stomach (Mayo). 



Utriculus mayoi Dall, Blake Gastr., p. 46. 



This shell recalls Bulla turrlta Moller, but is much larger, with 

 proportionately shorter spire, straighter sides and more width ante- 

 riorly. {Dall). 



R. FRiELEi Dall. PI. 21, fig. 8. 



Shell rather large, solid, polished opaque white, broader behind 

 than before its middle ; apex perforate, around which the margin of 



