MOLLUSCA OE THE ' CHATiLENGER ' EXPEDITIOK. 345 



resembles, on a still smaller scale, that feature in S. lignarius, L. 

 Compared to 8. onundus, Wats., this is a much more tiimid form, 

 and the sculpture is markedly different. 



3. SCAI'HAJS'DER GRACILIS, U. Sp. 



St. 73. June 80, 1873. Lat. 38° 30' N., long. 31° 14' W. West 

 of Azores. 1000 fms. Globigerina-ooze. Bottom temperature 

 39°-4. 



St. 78. July 10, 1873. Lat. 37° 26' N., long. 25° 13' W. Off 

 San Miguel, Azores. 1000 fms. Glohigerina-oozQ. 



Shell. — Thinnish, oblong, slightly flattened, a little narrowed 

 upward, 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, how- 

 ever, an additional finer line of minute stipplings is often interca- 

 lated. JEpidermis membranaceous, pale lemon-yellow. Colour 

 dead white, with occasional translucent longitudinal bands. Groion 

 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 forwards 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, retreat- 

 ing 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-shaj)ed umbilicus. Looking up the axis of 

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

 distinguished. H. 0*62. B.0'34. Grreatest breadth of mouth 0-24. 



IINN. JOURN. — ZOOLOGY, VOL. XVII. ' 26 



