18 Mr. R. Etlieridge on some Species 



states tliat W. Garibaldiana bears a close resemblance to 

 W. flavescens^ Lamarck, now living in Port Jackson, Sydney, 

 but it is less ovate, the beak is less elongated, and it has a 

 smaller foramen. 



Log. and Horizon. Coralline Limestone of Mount Gambler, 

 S. A. Cabinet of Mr. T. Davidson, F.R.S. 



Waldheimia Taylori^ sp. nov. (PL I. figs. 3 a, 6, c.) 

 Sp. char. Shell large, elongato-ovate, very inequivalve, 

 longer than wide, greatest width near the middle. Ventral 

 valve exceedingly convex, attenuated towards the beak, with 

 two slightly diverging obtusely rounded ridges proceeding 

 from the latter towards the front, where they become lost, 

 and enclosing between them a narrow space, which in its 

 upper part is rounded, but becomes flattened or a little concave 

 towards the front of the shell ; the lateral portions of the valve 

 are also flattened but not concave ; beak produced, incurved, 

 and truncated by an oblique circular foramen, contiguous to 

 the umbo of the dorsal valve, but separated from it by a small 

 deltidium. Dorsal valve as wide as the ventral, slightly 

 convex in the umbonal region, becoming almost flat to- 

 wards the front, but presenting in its longitudinal outline a 

 gentle continuous convexity. Lateral margins a little flexuous. 

 Surface marked by a few concentric lines of growth j shell 

 distinctly punctate. The position of the mesial septum is 

 traceable on the surface of the dorsal valve as a fine impressed 

 line ; interior otherwise unknown. Length 2 inches 3| lines, 

 width 1 inch 10 lines, depth 1 inch 5 lines. 



Ohs. Although, in the partial tripartite division of the ven- 

 tral valve, W. Taylori approaches W. Garibaldiana^ it may be 

 at once distinguished, irrespective of size, by the total absence 

 of all ribbing of the valves, and by the gently convex outline 

 of the dorsal valve, as compared with the tripartitely divided 

 similar valve of W. Garibaldiana. Terebratella compta, G. B. 

 Sowerby, is to be distinguished from the new species by the 

 following external characters — its much smaller size, more 

 triangular form of tlie dorsal valve, much larger deltidial area, 

 and consequent separation of the foramen and umbo, more 

 pointed outline of the front margin of the shell, more flattened 

 outline of the dorsal valve, especially in the umbonal region, 

 and a less incurved, but more obliquely truncated beak. Some 

 forms of Terebratula ovata, Sowerby, from the Cretaceous 

 series, are at first sight not unlike W. Taylori, but there is no 

 trace of the longitudinal depression of the dorsal valve of 

 that species or of the irregular surface-rugas. 



As we are at present unacquainted with the interior of this 



