REPORT ON THE GASTEROPODA. 473 



base of each whorl, there are two threads whose prominence slightly carinates each whorl ; 

 they nearly trisect the whorl, but that the highest is a little more than a third of the 

 whorl's height below the suture. There is another thread as broad, but less prominent, 

 halfway between the lowest carinal thread and that above the suture ; another, narrower, 

 appears less than halfway between the upper carinal thread and the suture. On the 

 upper whorls the upper carinal thread becomes much the most dominant and angulates 

 the whorls. Besides these, the surface is closely covered with unequal, fine, flat-topped 

 threads parted by very narrow square-cut furrows. There are of these threads about fifty 

 above the basal carina of the last whorl. On the base there are about the same number, 

 or rather more, of similar threads ; but the furrows are opener and shallower. Of these 

 basal threads some six or seven are rather stronger than the rest. They are all a little 

 interrupted on the base by the radiatirig lines of growth. Besides these lines, the whole 

 surface is exquisitely fretted with delicate, close-set, microscopic spirals (of which about 

 four go to j-oVij °f ari inch), and much more coarsely scored with longitudinal bars 

 (about jt^jtj of an inch apart), which in the furrows of the larger system of spirals appear 

 like the sharp edges of very thin lamellae, and which are probably in some way connected 

 with the epidermis of the shell. The whole of this microscopic system of sculpture is 

 present on the base. Colour porcellanous white, irregularly stained with suffused streaky 

 blotches of ruddy brown, which appear as minute sparse specks on the carinal threads 

 and on the base. Spire is high, narrow, and slightly scalar. Apex is broken. WJwrls: 

 There have evidently been 16 to 17 (but the first two or three are gone), of very regular 

 increase ; a few near the apex are angulated in the middle, but all the others are con- 

 cavely and slopingly shouldered below the suture, somewhat straight in the middle, and 

 slightly contracted below, where they project a very little at the suture beyond the top 

 of the succeeding whorl. The edge of the slightly concave and barely conical base 

 is right-angled. Suture defined only by the small ledge which projects above it. Mouth 

 square, bluntly pointed above, and rounded on the outer lip. Outer lip advances a little 

 on the edge of the base, bends outwards and is a little patulous to the upper carination, 

 from which point it runs straight to the outer lower angle, is flat across the base, and is 

 patulous and slightly channelled towards the point of the pillar, which it runs beyond. 

 The generic sinus is a mere open concave curve. Inner lip crosses the body more as a 

 polish than a glaze. Pillar perpendicular, white, with a slight twist, narrow, and with a 

 flattened and patulous rather than reverted edge. H. 1*55 in. B. 0*47, least 0"46. 

 Penultimate whorl, height 0'23. Mouth, height 0*25, breadth 0*23. 



This species is in form very like Turritella conspersa, Adams and Keeve, from the China Sea ; 

 but that has the lirations equal, the whorls are more angulated, and the angulation is not formed, as 

 in Turritella admirabilis, by a thread, but by a swelling in the whorl itself. The sculpture extremely 

 resembles Turritella bicolor, Adams and Keeve, China Sea ; but that is in form very much more 

 attenuated, has the suture much deeper, and the individual whorls are higher in proportion to their 

 breadth. 



(ZOOL. CHALL. EXP. — FAET XLII. — 1885.) Tt 60 



