230 THE PROCEEDINGS OF THE LINNEAN SOCIETY 



in uliim. balteo mediano, lato, duobus angustis balteis validis antice 

 marginatis ; apertura, elongata, lata ; labro tenui, apice acuto. 

 Long. 16, lat. 5^. 



Rather common. A small narrow somewhat acute species 

 differine: in this reo^ard in a marked manner from our living: A. 

 australis which is short and stout and A. mucronata which is 

 blunt and mucronate. The spire is covered with enamel so as 

 almost to obliterate the suture. In the last whorl the median 

 belt is rather broad. It is margined anteriorly with one narrow 

 thick cord and one broader and less distinctly defined. Posteriorly 

 there is one broad belt whose limits are not easily seen as the 

 suture is so indistinct. The outer lip is thin and the aperture 

 broad. Behind, the columella is twisted and the inner lip is very 

 indistinct. Fossil Ancillaria are not uncommon in the Vienua 

 and Paris basins, but this small species is more narrow and acute 

 than any of them. 



Prof. Tate remarks that the species is commonly about | of an 

 inch long, and that some of the specimens show the body whorl 

 to be coloured a violet brown, 



Nassa tatei. Plate 21, fig. 13. 



N. parva, ovata, spira quam apert longiori, subturrita, solida ; 

 anfr. 7, (4 embryon. Icevib.) convexis, conspicue costatis et liris sub 

 latis, regularibus, distantibus, clathratis ; interstUiis lineis mcrementi 

 conspicue corrugatis; costis {alt. anfr. 12) acutis, subelevatis, 

 aperiura ovata, intus lirata; labro varice incrassato, labio conspicuo, 

 reJlexOf expanso, plica posiica munito ; canali brevi lato profundo ; 

 recurvo. Alt. 7, lat. 8|. 



In this small species there are seven whorls ; the four apical 

 ones being smooth, the rest cancellate, with numerous sharp 

 raised ribs and transverse flat lira?. The interstices are rather 

 corrugated with the lines of growth. The mouth is large, with a 

 broad swollen varix on the labrum. The inner lip is expanded, 

 ■with a conspicuous posterior plait. The siphonal notch is deep, 

 broad, and abruptly recurved, and the throat is lirate. The shell 

 is in form like our existing Nassa compacta in size and shape, but 

 that shell is granular ; this is cancellate. It is mueh nearer to 



