SCAPHANDER. 247 



S. GRACILIS Watson. PI. 31, figs. 19, 20. 



Shell thinnish, oblong, slightly flattened, a little narrowed up- 

 ward, obliquely truncate at the top, where the outer lip rises like a 

 tooth on the right ; in front it is a little oblique toward the right, 

 very little expanded, rounded towards the point. The mouth is 

 pear-shaped and small for the genus. Sculpture : Longitudinals 

 the lines of growth are very slight. Spirals the whole surface is 

 dotted over with fine remote stipplings somewhat variable in size 

 and shape, running in rather oblique spiral lines, which are a little 

 crowded above and distant in front, where, however, an additional 

 finer line of minute stipplings is often intercalated. Epidermis mem- 

 branaceous, pale lemon-yellow. Colour dead white, with occasional 

 translucent longitudinal bands. Crown consists of the bluntly 

 rounded edge of a small shallow round pit, which is partly or wholly 

 choked up with the labial callus ; the line across the crown is very 

 oblique. Mouth rather small, pear-shaped, and nearly straight. 

 Outer lip slightly thickened and reflected on the crown of the shell, 

 from which it rises upwards and projects forward like a tooth ; from 

 this point it advances almost straight with a patulous and scarcely 

 convex edge to the beginning of the base, whence it sweeps round, 

 retreating and very patulous to the point of the pillar. Inner lip 

 very slightly convex above, almost straight in its oblique course 

 across the base; on all this part a thickish well-defined glaze is 

 spread on the front of the body ; as the mouth begins to widen, this 

 glaze is pressed out into a blunt angulation, almost a tooth, which 

 is prolonged to the left in the narrow-edged, flat-fronted, truncated, 

 twisted, concave pillar; here the reverted callus, which dies out at 

 the point of the pillar, has behind it a small shallow flat furrow 

 leading up into a pore-shaped umbilicus. Looking up the axis of 

 the shell, though the opening is rather narrow, two whorls can be 

 distinguished. Alt. O f 62 in. diam. 0*34. Greatest breadth of mouth, 

 0-24 inch. (Wats.). 



West of Azores, and off San Miguel, Azores, 1000 fras. 



S. gracilis WATS., J. L. S. Lond. xvii, 345 ; Chall. Gastr. p. 645, 

 pi. 48, f. 4. 



This is a long and narrow shell with little of the generic peculiar- 

 ity of shape, though the anterior splay form is recognizable. The 

 singular thickening of the pillar seems to increase with age. In the 

 three specimens from station 78 it is much more strongly marked 

 than in the somewhat younger shells from Station 73. The young 



