462 MK. H. BOLTON ON A MAKINE FAUNA IN THE [Nov. I907, 



bauds enumerated in Dr. Hind's ' Palaeontology of the Marine 

 Bands in the Coal-Measures.' x 



Pterinopecten papyraceus is especially characteristic o£ the Lower 

 Coal-Measures and of the shales of the Millstone Grit. It is abun- 

 dant in the lowest beds of the Upper Culm at Instow, Clovelly, and 

 other places in North Devon, but is as yet unknown in the South 

 "Wales and Forest-of-Dean Coalfields. Its presence in the Bristol 

 area would now suggest its presence in the adjacent coalfields also. 

 Notwithstanding the fragmentary character of the specimens, there 

 can be no doubt of the correctness of the determination — the lack of 

 bifurcation of the main ribs, and the intercalation of secondary 

 ones, being a well-known feature. 



PAL2EOLLMA KETIFERA, Hind MS. (PL XXX, fig. 10.) 



One specimen in the form of an internal cast, to which clings a 

 little of the original shell. In its general character it assimilates 

 to P. simplex, but differs from that species in being somewhat less 

 oblique, and in having fewer and finely-angulated ribs, which die 

 out as they approach the umbo, and do not exceed 20 in number. 

 The ribs show no trace of bifurcation, a specific feature of P. 

 simplex. 



Dr. Wheelton Hind informs me that this species has been already 

 recognized and described by him in a MS. paper upon a fauna at 

 the base of the Coal-Measures in Scotland. At his request, I refer 

 the species to P. retifera. 



Modiola, sp. nov. (PL XXX, fig. 11.) 



A single specimen only of this genus was found. In the absence 

 of more it is difficult to assign it to any species. The shell is 

 regularly and obliquely tumid, with a moderately-long hinge-line 

 and a well-marked, obtusely-rounded, postero-ventral border. 



Gasteropoda. 



Raphtstoma eadians, de Koninck. 



Several examples of this species were found ; they are of con- 

 siderable interest, as the species has been previously known from 

 only two horizons in this country, occurring in the North Stafford- 

 shire Coalfield in the marine band below the Gin-Mine Coal, and 

 at 500 feet below the Third Grit of Congleton Edge (Cheshire). 2 



Raphistoma (?) acuta, sp. nov. (PL XXX, fig. 13.) 



This form differs from R. radians in possessing a central, small, 

 acute spire of four or five whorls. Around the shoulder of each 

 whorl is a row of tubercles as in R. radians, but less defined, more 

 widely separated, and dying out upon the sides of the shell. The 

 inner whorls are of small diameter, as compared with the last two, 



1 Quart. Journ. Geol. Soc. vol. lxi (1905) p. 534. 

 . . 2 Ibid. - 



