478 THE VOYAGE OF H.M.S. CHALLENGER. 



16. Turritetta carlottce, Watson (PI. XXX. fig. 5). 



Turritella carlottce, Watson, Prelim. Keport, pt. 6, Journ. Linn. Soc. Lond., vol. xv. p. 222. 



Station 1G2. April 2, 1874. Lat. 39° 10' 30" S., long. 146° 37' E. Off East 

 Moncceur Island, Bass Strait. 38 to 40 fathoms. Sand and shells. 



Station 167a. June 27, 1874. Lat. 41° 4' S., long. 174° 19' E. Queen Charlotte 

 Sound, New Zealand. 10 fathoms. Mud. 



Shell. — High, narrow, conical, thin, translucent, with fine ruddy spiral threads, a 

 slightly impressed suture, and an angular flattened base. Sculpture : Longitudinals — there 

 are fine, thread-like, close-set curved lines of growth. Spirals — there are two principal, 

 t wo secondary, and very many minor spirals ; but the relative value of these varies a good 

 deal; they are little raised, but distinct. The base is covered with fine crowded spirals, 

 of which those near the edge are stronger than the rest. The microscopic system of 

 spirals is fine, sharp, and distinct. Colour yellowish ashy white, with a suffused ruddy 

 brown on the upper part of the whorls, and a stronger shade of the same colour defining 

 the more important spirals. The colour becomes altogether paler up the spire, and the 

 apex is white. Spire very perfectly conical ; but the profile lines are interrupted by the 

 impressed sutures. Apex small, rounded, smooth and glossy, consisting of 1^ embryonic 

 whorls ; the next whorl is slightly angulated, after which the regular sculpture begins. 

 Whorls 15, very slightly convex on the sides, contracting gradually upwards into the 

 suture ; towards the bottom of the whorls the contraction into the suture is shorter, 

 straighter {i.e., less convex), and more rapid; they are of very gradual and regular 

 increase. Towards the upper part of the spire the curve of the profile line of each whorl 

 becomes increasingly stronger. The base is flat, very slightly conical, sharply angulated, 

 and not contracted at the edge. Suture very slight, but well defined. Mouth small, 

 angularly rounded, a little higher than broad. Outer lip is a little drawn in and advancing 

 on the edge of the base, descends straight to the lower outer angle, is flat across the base, 

 and a little patulous in front of the pillar -point. The generic sinus in the outer lip is 

 parabolic in form. Inner lip : there is not (though the specimens are full-grown) even a 

 glaze across the body nor round the base of the pillar ; but on older specimens this may 

 probably exist. Pillar is a little concave, rather direct, with a thin rounded edge. 

 Epidermis is a very thin and delicate calcareous membrane, obviously not extraneous; it 

 adheres to the top of the spirals and stretches across their furrows. It is sparsely cleft by 

 minute gaping rents in the direction of the lines of growth, and the microscopic sculpture 

 of the shell is traceable in it, but rather on its under than its upper surface. H. 0'95 in. 

 B. 0-28, least 0'25. Penultimate whorl, height 0'15. Mouth, height 0'16, breadth 0*14. 



This species has some resemblance, both in forai and sculpture, to Turritella knysnaensis, 

 Krauss, but it is narrower, suture less impressed, whorls not so convex ; the embryonic apex is very 

 like, but in the Challenger species it is a little more swollen and depressed. 



