MOLLTTSCA OE THE c CHALLENGER ' EXPEDITION. 411 



Concb. 1868, p. 110, pi. ii. fig. 2), an Upper Tertiary fossil from 

 Piedmont; but is mucb tbinner, somewhat stumpier, witb a smaller 

 apex and more tumid body-wborl. 



17. Pleurotoma (Drillia) patjpera, n. sp. 



St. 191. September 23, 1874. Lat. 5° 41' S., long. 134° 4' 30" E. 

 Aru Island. 800 fms. Mud. Bottom temperature 39 0- 5. 



Shell. — Pusif orm, biconical, shortly and feebly ribbed, smoothish, 

 with a slightly constricted suture, of a yellowish-buff colour. 

 Sculpture. Longitudinals — above the middle of each whorl is a 

 row of tubercles, which stand out on the upper whorls rather 

 sharp and rounded, but on the lower whorls are elongated into 

 slight, oblique ribs, which tend to become obsolete on the last 

 whorl, and do not extend to the base. They are parted by shallow 

 rounded furrows, which are a good deal broader than the ribs. 

 There are about thirteen of these on eacb whorl ; they do not 

 extend in the least to the sinus-area above the tubercles. The 

 surface is very closely scored with coarsish lines of growth. Spirals 

 — the line of the tubercles forms a rather acute carinatiou, of which 

 there is hardly a trace in the curve of the whorls themselves. 

 The whole surface is covered Avith harsh, unequal, irregular, flatly 

 rounded threads, which are cut into small coarse granulations by 

 the lines of growth ; this sculpture is most developed on the base 

 and snout, less so in the sinus-area, least so of all on the rib -area. 

 Colour buff below the yellow epidermis, which is coarse and harsh, 

 but not thick ; the surface of the shell below it is smooth and free 

 from the granulated texture, but is curiously reticulated by 

 minute interrupted wrinkles, whose course is at right angles to the 

 lines of growth. Spire high and conical; its profile-lines are 

 little interrupted by the contraction of the suture. Apex eroded 

 in all the specimens. Whorls 10-11 (?), of regular, rather rapid 

 increase, shortish, with a largish, sloping, but hardly concave 

 shoulder above and a very slight contraction below. They are 

 angulated by the projection of the line of tubercles, but are other- 

 wise little convex ; the last is a little tumid and considerably elon- 

 gated, a little contracted on the base, and gradually drawn out 

 into the conical, straight, longish, and at the end smallish snout. 

 Suture rather deep, and strongly marked by the angle at which 

 the superior and inferior whorls meet. Mouth buff-coloured 

 within, rather long and narrow, pear-shaped, pointed above, with 

 a longish, broad, and open canal below : the direction is very 



