MOLIiUSCA OF THE ' CHALLEFaER ' EXPEDITION. 389 



Shell. — Thin, clialky white with a tiuge of buff, fusiform, with 

 a high subscalar spire, small mamillary apex, long small snout, 

 rounded whorls scored by thin procumbent lamellae. Scidpture. 

 Longitudinals — there are on the later whorls from 15 to 20 

 procumbent lamellge, between these are slight lines of growth. 

 Spirals — there are a few quite irregular and obsolete rounded 

 threads. Colour chalky white with a tinge of buff. Spire high, 

 subscalar. Apex small, consisting of barely two smooth, globose, 

 embryonic whorls, of which the extreme tip is slightly turned 

 down on one side and immersed. Whorls 7, slightly flattened 

 above, couvexly cylindrical below, with a very slight contraction 

 above the suture ; the last is a little tumid, with a produced 

 conical base running out into a long, small, twisted, and upturned 

 snout. Sutlers slightly impressed, oblique. Mouth oval, bluntly 

 pointed above, drawn out into the long, narrow, and oblique canal 

 in front. Outer lip thin, arched, slightly reverted and patulous ; 

 very obliquely cut off and emargiuated at the point of the canal. 

 Inner lip yerj concave above, convex at the entrance to the canal, 

 from which it runs with a twist and very obliquely to the left ; 

 the labial glaze is thin and somewhat indefinite. H. 0'8. B. 0"32. 

 Penultimate whorl, height 0-17. Mouth, height 0-43, breadth 

 0-2. 



I have described this as a new species with very great reluc- 

 tance. My own opinion is that it is a large thin variety of T. trim- 

 catus, Strom; and that opinion is shared by Mr. E. A. Smith. Dr. 

 G-wyn Jeffreys, however, and Prof. Gr. O. Sars decidedly hold it as 

 distinct; and their extensive acquaintance with the large northern 

 variety of T. truncatus makes their judgment of great weight. 

 Along with the specimen of this species which I submitted to 

 Prof. Sars I forwarded another shell, sadly broken, which I con- 

 sider different and new, and have named T. auclitus, from St. 150, 

 and which I sent thinking it might be his T. clavatus. Prof. 

 Sars's own letter will best convey his opinion regarding both of 

 these forms : — " I have examined your shells very closely ; they 

 show a very perplexing similarity in form and sculpture to nor- 

 thern Trophons The one specimen is certainly very 



nearly related to T. truncatus, Strom ; but still I find, on comparing 

 it with Norwegian specimens of the species, some differences. 

 Thus the shell, though larger, is less solid, and the longitudinal 

 ribs are also somewhat different both in number and in form ; in 

 all my specimens of T. truncatus they are distinctly lamellar and 



