104 HORN EXPEDITION— PALEONTOLOGY. 



periphery, beneath which is a narrow, feebly-impressed band ; base convex, imper- 

 forate, aperture rhombic ; columella arched in the vertical plane, vei'y convex 

 transversely. Height, 12 mm. ; width, 10-5 mm. ; aperture, 6 x G mm. 



The weathered test does not permit a correct interpretation of the infra- 

 peripheral band ; but, in association with the trochiform shape of the shell, is 

 suggestive of Scalites rather than Et<nema. 



Loc. — In limestone. Middle Valley at Tempe Downs, Ilpilla Gorge, and at 

 camp on Laurie's Creek. 



Ophileta gilesi, Etheridge, fils. 



Ref.—x., p. G, t. 1, figs. 6-8. 



The species was founded on a small cast. Tiie shell shows that the three 

 anterior whorls are concave between the keel-like front margin and the suture ; 

 the spire is hardly elevated above the last whorl, whilst the apical whorls are 

 sunken ; the ornament consists of linear threadlets, oblique, slightly retroverted at 

 the keel, five in a width of one mm., probably indicating a labial sinus, and thus 

 connecting with Raphisloma. Dimensions of two largest specimens : — Diameters, 

 17 mm. and 13 mm. ; height, 7 mm.; diameters?, 19 mm. and IG mm. ; height, 7 mm. 



Loc. — In limestone, camp at Laurie's Creek and north of Tempe Vale. 



Pleurotomapia (P) larapinta, sp. nov. (Plate III., Figs. 29^?, 29/;.) 



Sp. c/iar. — Shell depressed conoid, whorls (number T) subimbricate over the 

 suture. Last whorl with a flange-like keel, narrowly furrowed at the periphery ; 

 flatly convex to the suture, narrowly precipitous below the keel, thence flatly 

 convex to the imperforate base. Aperture subquadivate. The ornament consists 

 of revolving threadlets, fifteen in a width of four mm. on the upper surface of the 

 body-whorl, about twenty on the posterior half of the base. Length, incomplete, 

 12 mm. ; width, 13 mm. 



Loc. — In limestone, Middle Valley, Tempe Downs. 



Imperfectly-known Euomphaloid Shells. 



(1.) A common fo-ssil in the Larapintine quartzites at Tempe Downs, north of 

 Tempe Vale, between Petermann Creek and Tempe Downs, and also at Finke 

 Gorge, is that indicated by a basal impression, which has been figured by 

 Etheridge, vi., t. 3, figs. 9, 10. 



