150 



Surface ornamented with thin, angular, elevated, curved, 

 radial ribs, 24 in number, eight of which occupy the abruptly 

 sloping post-umbonal area, insterstices wider than the ribs ; 

 the whole surface crossed by thin distant concentric lira?, 

 which produce serratures on the radial costse. 



Lunule deep and broadly cordate. 



Interior pearly, ribbed towards the ventral and posterior 

 margins corresponding with the exterior sulcations ; anterior 

 and posterior margins thin, crenulated. 



Eight valve with a tooth-like callosity under the lunule, and 

 a long laminar lateral tooth on the posterior side. 



Dimensions. — Antero-posterior diameter, 5 ; umbonal ventral 

 diameter, 5 ; sectional diameter of right valve, 2'25 milli- 

 metres. 



Locality. — Calciferous sandstone, with gastropods, Eiver 

 Murray Cliffs, near Morgan. 



Verticordia pectinata, spec. nor. Plate xiv., fig. 13. 



Triangularly ovate, slightly convex ; anterior side somewhat 

 produced and rounded ; umbo small, curved towards the front, 

 situated a little behind the middle line ; front dorsal margin 

 concave, post-dorsal margin convex, gibbous ; ventral margin 

 slightly arched medially, rapidly ascending posteriorly to the 

 subacuminate extremity. Ornamented with twelve broad, 

 rounded, radial undulations about equal in breadth to the con- 

 cave furrows ; the whole surface minutely granular, which ia 

 produced by the intersection of radial and concentric striae. 

 Interior of left valve pearly, edentulous ; ventral margin of 

 valve thin, broadly crenulated. 



Dimensions. — Antero-posterior diameter, 35 ; umbo-ventral 

 diameter, 3 millimetres. 



Locality. — Lower beds at Muddy Creek. 



FAMILY CARDIIL\E. 

 Ge:nt/s Caedium. 

 synopsis of the species. 

 "Whole surface ornamented with more or less similar radial 

 ribs. 



a. Yalve rotundly-quadrate. 



Eibs, 50, flat, and smooth. C. pseaclomagmim. 



Eibs, 70, flat, and smooth ; those on the posterior slope 

 with small tubercles. C. septuagenarium. 



Eibs, 60, flat, granulated on the margins. 



C. moniletectum. 

 p. Valve ovate, oblique ; 65 ribs. C. Victoria, 



c. Valve trapezoidal. C. cucidloides. 



