182 THE VOYAGE OF H.M.S. CHALLENGEK. 



the spire, and tend to become obsolete on the body- whorl ; the lines of growth are fine, 

 smooth, and unequal. Spirals — a strongish furrow below the suture cuts off the top of 

 the ribs as a row of nodules ; the middle of the whorls is scored, especially in the 

 intercostal furrows, with remote impressed lines, which are more or less obsolete ; on 

 the front of the base are 4 to 6 strongish, flat, subimbricated threads : coiling round 

 the base of the pillar is a broad shallow furrow, in which the longitudinal ribs are 

 visible ; below this is a prominent thread, while the point of the pillar is scored by 

 about 4 sharpish threads with broader furrows. Colour livid, with more or less of 

 brown ; the point of the pillar is white, as are two bands, one at the suture and the 

 other above the periphery. Spire short, conical, subscalar. Apex small but blunt, the 

 three smooth, rounded, globose embryonic whorls being somewhat depressed; they are 

 also markedly smaller than the succeeding regular whorl. Whorls 9, conical, slightly 

 convex, the last a little tumid. Suture impressed and slightly canaliculate. Mouth 

 oval, pointed, channelled and nicked above, with a short oblique canal in front. Outer 

 lip sinuated above, straight, and rather contracted to the point of the base, where it is 

 patulous ; it is toothed within, serrated on the anterior edge, right-angled at the canal, 

 the edge of which is sharply margined by the infrabasal thread. Inner lip concave and 

 toothed above, straight and bluntly tubercled on the pillar, the point of which is flanged, 

 and down which the edge of the labial callus projects prominently, leaving a shallow 

 chink behind it. Operculum thin, yellow, oval, triangular, with a slightly serrated outer 

 and inner edge. H. 0'8 in. B. 0'45. Penultimate whorl, 0*18. Mouth, height 0-33, 

 breadth 0"24. 



Mr Marrat of Liverpool, whose labours on the genus Nassa in particular are well known, and 

 who has had the goodness carefully to examine the whole of the Challenger species of the group, 

 considers this species to be his Nassa laevigata (=glabella, Marr. nee Sow.), an opinion which I am 

 not able to accept. With a considerable general resemblance, the form of the shell is very- 

 different. In Nassa laevigata the shortness and breadth of the last whorl gives a contour-line totally 

 unlike that of Nassa levukensis, which is narrow at the periphery and comparatively long in the 

 base. It has points of resemblance to Nassa monile, Kien., to Nassa algida, Reeve, to Nassa coronata, 

 Lam., and to Nassa crenulata, Brug., but is certainly distinct from them all. It most of all 

 resembles one of the depauperated forms of Nassa canaliculata, Lam., in some of which the 

 canaliculation of the suture becomes very obsolete ; but in none of these is there so sharp a flange 

 round the anterior canal, none have so deep a furrow at the origin of the pillar, nor so sharp a 

 thread in front of that furrow, and in all the apex has a broader base, and is higher, sharper, more 

 conical. The operculum, too, is quite unlike, being in these very much smaller, more oval, and 

 without serrated edges. 



16. Nassa (Zeuxis) crenulata, Bruguiere. 



Buccinum crenulatum, Bruguiere, Encycl. method., vers., vol. i. p. 271, sp. 37, pi. ccexeiv. fig. 6. 



,, „ Lamarck, Anim. s. vert., vol. vii. p. 267 (ed. Desh.), vol. x. p. 161, sp. 13 



(sec. Nasses). 



