348 PROCEEDINGS OP THE GEOLOGICAL SOCIETY.. [Feb. 26, 



Xeritina staeelnensis, Forbes, Quart. Journ. Geol. Soe. vol. vii. 

 t. 5. f. 13. p. 110. PI. XII. fig. 6. 



Shell small, ovate, of a brown born-colour, spire sbort but pro- 

 minent, body-whorl slightly impressed towards the suture, orna- 

 mented with close and fine transverse stria? ; aperture ovate. 



Dimensions. — Length -£$ inch, breadth ^ inch. 



Horizon. — Infra-Oxfordian Estuarine beds, Staftin {Forbes, B. T.) ; 

 Tor-Vaig, near Portree (B. T.) ; and Loch Bay, Dunvegan (J. B.). 



Numerous specimens in a state of perfect preservation were ob- 

 tained from a greenish-coloured sandy marl rock, on the west slope 

 of Tor-Vaig, associated with Oyrena Brycei and Melania ? inermis : 

 many of them have the spires eroded ; but all retain coloration. The 

 original description of this species is based upon two badly pre- 

 served specimens, which appear to be more or less in the condition 

 of casts ; I have therefore amended the description and refigured 

 the species. 



Xeritina arata, nov. spec. PI. XII. fig. 7. 



A minute hemispherical shell, with a short but conspicuous spire, 

 and an inflated body-whorl ornamented with a few thick transverse 

 costae. 



Dimensions. — Length and breadth about -^ inch. 



Horizon. — Infra-Oxfordian beds, Loch Bay, Dunvegan (J. B.). 



Belated to N. costulata, Desh., of the Bath Oolite, but separable 

 from it by the number and strength of the costse, and by the ex- 

 serted spire. 



Valvata precursor, nov. sp. PL XII. fig. 9. 



Resembles V. helicoides, De Loriol ; but the sutures are not so 

 deep, and tbe whorls do not increase so rapidly. It exhibits much 

 the same variations of form, size of umbilicus, and convexity of base 

 as are presented by that species. 



Xot one of numerous specimens collected is in a good state of 

 preservation. 



Position. — Associated with Melania inermis, Neritina staffinensis, 

 Mytilus (cf.) liihodomus. Infra-Oxfordian Estuarine beds over 

 Prince Charles's Cave, Portree {B. T.). 



Melania ? inermis, nov. spec. PL XII. fig. 5. 



Shell ventricose, longer than broad, spire very short, composed 

 of very narrow, somewhat convex whorls; body- whorl occupy- 

 ing nearly the whole length of the shell. Aperture very narrow 

 posteriorly, expanding anteriorly; columella callous; outer lip 

 sharp. 



Dimensions. — Length -^ inch, breadth -^ inch. 



Position. — Infra-Oxfordian Estuarine beds, Tor-Vaig near Por- 

 tree and Vaterstein (B. T.). 



The generic position assigned to this shell is doubtfully the true 

 one. The general form suggests an affinity with the Tomatellida> ; 



