120 



interrupted by the radii. Auricles small, anj^ular ; hinge line 

 narrow, with four or five longitudinal plications on each 

 margin. Inner margin of valves crenulated. 



Dimensions. — Yentro-dorsal diameter, 8 5 ; lateral diameter, 

 6 ; thickness through both valves, 5. 



Localities. — Muddy Creek, Hamilton ; Mount Gambler, white 

 polyzoal limestone {R. T.). Probably this species at Table 

 Cape, Tasmania. 



In this species the denticulations of the hinge are longitu- 

 dinal and marginal ; whilst in L. alticosta they are transverse, 

 and occupy the whole length of the hinge-line. 



Mr. ]^ 'M. Johnston has described a shell under the name of 

 CucullcEa minuta, op. cit., which from its description may be 

 either Limea transenna, or conspecific therewith. He moreover 

 states that it is not unlike Limatula suhauriculata [i. Jeffrey- 

 siana\ in general appearance. I transcribe its diagnosis: — 

 " Shell very minute, thin, obliquely oval ; hinge-line straight, 

 narrow, with three or four teeth, oblique at extreme corners ; 

 surface of valves ornamented with fine radial ridges, and 

 crossed by lines of growth ; towards the margin the ridges are 

 lamellar, and are also imbricated where intersected by the 

 concentric lines of growth ; margin finely crenulate ; long. 3 

 mil., lat. 2\ mil., thickness at umbo of both valves \\ mil. 

 Eare, Table Cape." 



Limea alticosta, &^ec. nov. Plate iii., fig. 8. 



Shell minute, shortly oval, slightly inequilateral, dorsal line 

 short, straight ; umbo central, elevated, obtusely produced ; 

 auricles small, unequal. Eayed with 14 elevated subacute ribs, 

 narrower than the interspaces, faintly striated transversely. 

 Hinge margin with from six to seven transverse denticles on 

 each side of the ligamental socket. Ventral margin strongly 

 crenate. 



Dimensions. — Length and height exceeding two millimetres. 



Locality. — Adelaide bore (one ex.). 



This species resembles the type of the genus, L. Sarsii, 

 but is more inequilateral and has plain ribs ; its similarity to 

 L. aciiticosta, Munster, of the European Lias is very striking, 

 from which it differs externally by its less oblique shape, whilst 

 the hinge teeth of that species are longitudinal on the outer 

 margins, and not transverse throughout the cardinal line. 



FAMILY SPONDYLIID^. 



Genus Spoxdylis. 



synopsis of species. 

 Einely ribbed between the primary ribs. S. pseudoradula. 



Coarsely ribbed between the primary ribs. S.gcederopoides. 



