MOLLTJSCA OF THE ' CHALLENGER ' EXPEDITION. 597 



corresponding varices, scarcely visible on tlie earlier whorls, and 

 chiefly marked on tlie last by tlie series of long tbiii front-fur- 

 rowed spines wbicli adorn tbem : of these spines there are 6 (or 7 ?) 

 on the last varix, 6 on penultimate, and 5 on the preceding one ; 

 the highest is very little bent, and rises on each whorl high above 

 the apex, being almost parallel to the axis of the shell; the others, 

 which are alternately short and long, are more or less bent, and 

 incline upwards : there is only one spine on each varix of the 

 spire ; these varices are prolonged down the snout ; and each is 

 armed with about 6 long thin horizontally straight but forward- 

 bending front-furrowed nearly equal spines, between each pair 

 of which in front is a small, fine, procumbent thorn ; the system 

 of triple varices begins in the course of the second regular whorl : 

 above this point the shell is scored across by from 10 to 16 scars 

 of old mouth-edges, which at top and bottom of the whorl pro- 

 ject into little tubes, hollow, and in front open ; the lower row 

 of these tubes is only visible on the first regular whorl, and is 

 gradually buried by the overlap of the suture: between the 

 varices there are no ribs, bat only fine discontinuous undulations, 

 with superficial regular puckerings and lines of growth, which 

 behind the lip exhibit fine crowded laminae. Spirals — there are 

 on the last whorl 3 strongish depressed rounded threads corre- 

 sponding to the 3 largest spines ; corresponding to the smaller 

 spines are smaller threads ; between all of these are one or more 

 fine threads parted by shallow furrows wider than they : besides 

 all these the whole surface is scored mth very minute, rather 

 distant, and somewhat irregular threadlets ; the highest thread, 

 connecting the series of largest spines, forms a strongly angulated 

 shoulder-edge on the upper whorls. Colour ashy white with a 

 rufous tinge, which is strongest on the spines and the point of 

 the snout ; the apex is waxy and subruf ous ; the mouth-edge all 

 round is porcellaneous white, with one or two chestnut specks on 

 the outer lip, the largest and brightest being just at the top of 

 the mouth. Spire rather low, conical, scalar. Apex consists of 

 2 1 rounded, more or less depressedly globose whorls, of which 

 the earliest is always deformed as if crushed ; the others are 

 smooth, and are parted by an impressed suture ; they terminate 

 abruptly in a patulous and prominent mouth-edge, which has a 

 small sinus at the top. Whorls 7, angularly carinated above, and 

 with a sloping shoulder between the suture and the keel ; the 

 upper whorls are subcylindrically conical, the last tumid and 



