120 



RECORDS OF THE AUSTRALIAN MUSEUM. 



The importance of this fossil from a stratigraphical point of 

 view demands that it shall receive a name, for instance, that of — 



LiNGULA GREGARIA, sp. nOV. 



(Fig. 14). 

 S]). Char. — Ventral valve elliptical, narrow, greatest width at 

 about the middle of the length; sides sub-parallel; front gently 

 rounded; umbonal region attenuated, the umbonal 

 slopes extending well forward ; beak small, quite 

 posterior; general surface gently convex, decidedly 

 triareal, divided into the two umbonal slopes and 

 the central triangular surface, the latter somewhat 

 flattened, and widening towards the front, defined 

 by two radii, which separate it from the umbonal 

 slopes. Sculpture consisting of the finest, almost 



Fig. 14. 



microscopic, concentric lines. Average length, 6h 

 mm.; breadth, 3 mm. 



06s. — L. gregaria is associated with a Lepidodendron in the 

 Knorria-condition, probably of the L. veltheimianum group, 



Zoc. — Nyrang Creek, about five miles from Canowindra, N. S. 

 Wales. 



6 Dana— Wilkes U.S. Explor. Expedn., Geology, x., 1849, p. 695, pi. ii., 

 g. 6 a and b. 



