155 



An impressed line on the surface of the brachial valve, 

 extending for about one-third its length, indicates the existence 

 of a mesial septum. Interior unknown. 



A small shell, bearing an external resemblance rather to W. 

 Vincentiam than to any other known species, possesses internal 

 characters totally different from those of any Waldheimia. 

 The septum is remarkably long, extending through a distance 

 of '65 inch of a total curvilinear length of the brachial valve of 

 "85. The loop is broadly compressed, the forward limb is con- 

 duplicate, and is excessively expanded anteriorly and confluent 

 with the returning portion of the loop ; at this point the depth 

 is -^th of an inch. 



Dimensions. — Length, 2;} inches; breath, 1 T ^ inch; depth, 

 l^j inch. 



Observation. — The only species from the Australian Tertiaries 

 that bears any resemblance to W. Vincentiana is W. giyas (T. 

 Woods), which has, however, a more elongated shape, and is 

 more attenuated and conspicuously biplicated at the front. 



Locality and Horizon. — In the raggy limestones about one 

 mile south from Port Vincent (or Surveyor's Point), west coast 

 of St. Vincent's Grulf (two examples). 



Waldheimia Taylori, Etheridge. Plate xi., fig. 2. 



Ref. — Annals and Mag. of Nat. Hist., vol. xvii., p. 18, t. 1, 

 f. 3. 1876. 



" Shell elongato-ovate, longer than wide ; greatest width near 

 the middle. Peduncular valve exceedingly convex, with two 

 slightly diverging obtusely-rounded ridges proceeding from 

 the beak towards the front, where they become lost, and en- 

 closing between them a narrow space which in its upper part 

 is rounded, and 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 brachial valve, but separated from it by a small 

 deltidium. Brachial valve, slightly convex in the umbonal 

 region, becoming almost flat towards 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 ; shell distinctly punctate. 



Length, 2 inches 3| lines ; width, 1 inch 10 lines ; depth, 1 

 inch 5 lines. 



Locality and Horizon.— Coralline limestone of the Murray 

 Eiver cliffs, near the Great Bend, S. Aust. Mas. Prac. Geology, 

 London." Etheridge. 



This shell is imknown to me, unless I have mistaken for it 

 a narrow form of W. Corioensis, which occurs at Mannum. It 



