262 BET. K. BOOG WATSON ON THE 



base o£ the body-whorl, as it comparatively is in JV. Montagui. 

 The umbilicus, too, is less open, and there is no trace of the 

 umbilical pillar and superior furrow of that species. Than JV. 

 bullosa, Eve., this species is rounder in the mouth, higher in 

 the spire, and opener in the umbilicus. 



8. Natica xantha, n. sp. (favdos, yellow.) 



St. 150. Feb. 2, 1874. Lat. 52° 4' S., long. 71° 22' E. Between 

 Kerguelen and Heard Island. 150 fms. Rock. Bottom tem- 

 perature 35 D, 2. 



Shell. — Strongish, conically globose, slightly pointed below at 

 the base of the mouth, glossy, bright yellow, but whitish around 

 the umbilicus, which is a mere cleft. Sculpture. Longitudinals 

 — there are very slight, rather unequal, hair-like lines of growth. 

 Spirals — the surface is covered as usual with extremely faint 

 superficial wavy lines and furrows, besides which is a system of 

 still more superficial microscopic sharp straight scratches, which 

 it is very difficult to see at all. Colour pure porcellanous white 

 under the brilliant yellow epidermis, w r hich is very thin, glossy 

 and rather persistent. Spire high, but blunt at the top, which is 

 somewhat eroded. Apex large, bluntly rounded. Whorls 4, the 

 first one is large, and the shell increases very regularly; they 

 are tumid and regularly rounded, and rise high above the succeed- 

 ing ones ; there is a slight and narrow swelling below the suture, 

 with a very slight and shallow compression of the shell below 

 this swelling. Suture channelled, but not broadly nor deeply so ; 

 it is considerably and increasingly oblique. Mouth large, open, 

 broadly oval, with a slight flattening of its curve on the left side ; 

 its upper corner is very accurately rectangular. Outer lip, open 

 but not very patulous, is a most regular curve in its whole sweep, 

 which passes almost without change into the curve of the pillar. 

 Inner lip is very slightly concave, till towards the front of the 

 pillar it curves round to the right to meet the outer lip ; a very 

 slight pad fills up the upper edge of the mouth, a very thin 

 transparent and straight-edged callus carries it across the body ; 

 over the umbilicus it is slightly thickened and a good deal re- 

 verted ; at the point of the pillar, where it becomes adherent, it is 

 encroached on very slightly by a small furrow, which runs out of 

 the umbilicus parallel to the pillar ; below this point the lip has a 

 narrow, rounded, and expanded edge. H. 0'54. B. 0*47. Pen- 

 ultimate whorl, height 023. Mouth, height 0'42, breadth 0*3. 



