300 Mr. F. M'Coy on the Fossil Botany and Zoology 



Pleurorhynchus australis (M'Coy). PI. XVI. fig. 4. 



Sp. Char. Alseform or transversely subtrigonal, gibbose, length 

 nearly two-thirds the width ; posterior side forming a com- 

 pressed narrow wing ; anterior face obliquely subtruncate, con- 

 vex, divided into three nearly equal tumid compartments by 



. two impressed furrows from the beak ; body of the shell and 

 posterior side radiated with rather coarse irregular ridges from 

 the beak ; anterior face finely striated longitudinally. 



This resembles the P. mmax (Phil.) in the striation of the an- 

 terior face being so much finer than that of the middle or pos- 

 terior parts of the surface ; it differs in having the anterior face 

 not only much more finely striated, but divided into three parts 

 by distinct furrows ; while from the Cardium irregulare and C. 

 strangulatum (Kon.), which have the anterior face so divided, but 

 smooth, it is distinguished by this latter character, and also by 

 wanting the mesial strangulation of those species. Length of 

 small specimen 8 lines, width 1 inch. 



Not uncommon of larger size in the sandy schists of Wollon- 

 gong, N. S. Wales. 



Allorisma curvatum (Mor.). 



Common in the sandstones of Darlington, Wollongong and 

 Glendon, N. S. Wales. 



Orthonota compressa (Mor.). 

 In the calcareous schists of Harper's Hill, N. S. Wales. 



Orthonota costata (Mor.). 

 Common in the sandstone of Wollongong, N. S. Wales. 



Modiola crassissima (M'Coy). PI. XV. figs. 2 & 3. 

 Sp. Char. Transversely ovate, very gibbose ; beaks small, nearly 

 terminal ; anterior side forming a small rounded lobe beneath 

 the beaks, separated from the body of the shell by a strong 

 sinus in the ventral margin, from which a shallow concavity 

 runs towards the beak ; posterior side wide ; hinge-margin ele- 

 vated, four-fifths the width of the shell in length, compressed, 

 angulated, posterior end broadly rounded; ventral margin 

 convex ; shell very thick ; surface with a few concentric waves 

 of growth, and marked towards the posterior inferior angle 

 with a few distant obsolete ridges extending obliquely from 

 the beaks. 



Length 5 lines, width 1 inch 7 lines, height of cardinal angle 

 11 lines (occasionally 3£ inches wide). 



Not uncommon in the schists of Harper's Hill, N. S. Wales. 



