PERMO-CARBONIFEROUS PELECYPODA-^ETHERIDGE. 183 



between them and the dorsal margins the surface of the valves is 

 somewhat hollowed, and before them are shallow ill-defined cinc- 

 tures dying off towards the insinuated points on the ventral 

 margins ; umbones inconspicuous ; anterior adductor impress- 

 ions triangular, of medium size but strongly marked, deep 

 anteriorly and superiorly, with well marked bounding grooves on 

 the posterior sides ; posterior adductor impressions inconspicuous, 

 flattened, placed high up under the hinge lines, and immediately 

 at the ends of the dorsal margins : indications of scars exist within 

 the umbonal cavities. Ligamental fulcral impressions wide and 

 shallow ; ligamental pits transversely elongated, each giving off 

 an oblique and posteriorly directed ridge, and forming the anterior 

 boundaries of the shallow cinctures. Pallial scars well marked, 

 continuous (i.e., not broken up), the surfaces below rapidly thining 

 away o the ventral margins. 



Obs. — All the specimens are in the form of internal casts, as an 

 impure somewhat concretionary limonite, allowance must there- 

 fore be made in applying the above description to future examples 

 with the test preserved. What the nature of this envelope was we 

 are ignorant, but on a few of the specimens there are apparently 

 faint indications of posterior radiating costae. An example from 

 the Upper Marine Series of Wollongong, possessing the outline 

 and measurements of this species, and with the test preserved, 

 exhibits a few radiating posterior costas and strong imbricating 

 larainpe of growth that may represent the more perfect condition 

 of S. farleyensis, but it cannot be accepted as by any means 

 certain. 



Dana described two shells as Cardinia ? recta and C? cuneata* 

 both from the Illawarra District differing greatly in outline from 

 those forms I have made typical of the new name Stutchburia, 

 but the internal features depicted in his figures are precisely 

 similar to those of .S". farleyensis. They seem to be edentulous, 

 and the only point allying them with Cardinia ate the nasute 

 posterior ends. It is possible, therefore, that the shells in question 

 may be species of Stutchburia, in which case the generic characters 

 of the latter, will of necessity require to be slightly modified. 



The internal casts of S. farleyensis occur in great numbers in 

 the Lower Marine Series at Farley, near West Maitland, and it 

 is essentially a Lower Marine species, but the Geological Survey 

 Collection contains a shell from the Upper Marine Series of 

 Richmond Vale, Parish of Stanford, County Northumberland, of 

 somewhat larger dimensions than the measurements above given; 

 otherwise it agrees in every detail with my description. This 

 bears out the suggestion that the shell found at Wollongong, with 

 the test preserved is also S. farleyensis. 



* Dana— Wilkes' U.S. Explor. Exped., x., 1849, pi. 4, f . 5a, 6, and f. Qa - e. 



