106 



the existing fauna of Kerguelen Island and otner similar 

 Southern positions. The TurriteUa resembles T. Hookeri from 

 the Antarctic, without locality; the Xatica has no near analogue, 

 and the genera C Inane and Gari are not represented in high 

 Southern latitudes : nevertheless, it is not improbable that the 

 two species of Mytilus may belong to recent species. 



The fauna indicates nothing specialised, except that of dis- 

 tinctness of species, to separate it from that of a modern 

 deposit : and in the absence of distinctive genera of Palaeogene 

 age, I must refer the deposit to Neogene without any subordinate 

 assignment. 



Notes ox the Fossils. 



Natiea Tremariei, spec. nov. PL ii., figs. 4a-4c. 



Shell depressedly hemispheric : whorls four and a half, marked 

 with growth-lines, but without spiral sculpture. Aperture 

 lunate. Umbilicus wide : a small callus is reflected over the 

 upper portion of the umbilicus. 



In shape this fossil species is like the recent X. ampla and 

 X. Incei of the same size, but the spire is obtuse and less elevated 

 than in N. Incei, more elevated than in X. ampla, and regularly 

 convex below the suture ; the umbilicus is somewhat similar to 

 that of N. ampla. 



Diameters, 19 and 12 : height, 10 mm. 



TurriteUa Hallii, spec. nov. PL ii. , figs. 3a-36. 



Shell broadly conical, a little rounded at the basal angle and 

 on the base. Apex not known. Whorls ten, biangulated, much 

 constricted below, and more gradually contracted above. 



The ornament consists of two strong keels, one at each margin 

 of the side, dividing each whorl into three approximately equal 

 widths : the space between the keels is flattish or slightly eon- 

 cave. In addition there are line spiral threads, usually alter- 

 naternately large and small, six on the intercarinal space, and 

 six on each of the sutural slopes. 



Aperture quadrately oval, higher than it is broad ; outer lip 

 not preserved, though there are traces on the anterior part of the 

 last whorl of curved growth lines, indicating a broad shallow 

 sinus : columella somewhat arched and thickened (not dilated at 

 the front). 



Length, 39 : breadth, 1 2 • 5 ; height of last whorl, 12 mm. 



Among the few bicarinate species of the genus it makes some 

 approach to T. ambulacrum, Sow., Tertiary in Patagonia and 

 Chatham Islands, which has the wiiorls not so quadrate, and the 

 encircling ribs are of unequal size. It simulates T. Hookeri T 

 Reeve, an Antarctic species, but, judging by the figure, it is 



