94 GASTEROPODA OF THE INFERIOR OOLITE. 



13. Purpurina tabulata, sp. nov. Plate II, figs. 4 a, b, c. 



Description : 



Length of a large specimen . . .20 mm. 



Ratio of width to length . . . 80 : 100. 



Length of body- whorl to entire shell . . 70 : 100. 



Spiral angle . . . .90°. 



Shell conoidal, subglobose, almost imperforate. Whorls about six, angular and 

 widely tabulate, slightly tumid on the flanks. The longitudinal ornament is very 

 feeble, especially in the body- whorl ; it is better shown on the tabular area, where 

 the costas are split by lines of growth. The keels are delicately crenulate. The 

 spirals are regular, numerous, and rather fine ; they do not extend over the 

 tabular area. 



Aperture ovate to subquadrate, wide, and bearing considerable resemblance to 

 that of P. elaborata. 



A less tumid variety (PI. II, fig. 4 d, e), with better developed costae, serves to 

 connect this species with P. carta (PI. I, fig. 6 a, b), which, however, has well- 

 developed costse and a somewhat longer spire. This variety might be called 



P. SUBCORONATA. 



Relations and Distribution. — P. tabulata is near to P. coro?iata, H. and D. (' Foss. 

 Mont.-Bellay,' p. 25, pi. i, fig. 7), but that small and tabulate species is beautifully 

 cancellated. 



Rather rare in the Sowerbyi-hed of Bradford Abbas and Stoford. 



The following list summarises the results as regards the Purpurines, strictly 

 so called, of the Inferior Oolite in England. 



Bellona Group. 

 Purpurina elaborata, M. and L. Purpurina curta, sp. nov. 



• — " aperta." — parcicosta, sp. nov. 



— cancellata, sp. nov. — aspera, sp. nov. 



— bellona, D'Orb. — calcar, sp. nov. 



— — — var. pagoda. 



Inflata Group. 



Purpurina inflata, Tawney, Purpurina rotunda, sp. nov. 



— cf. Sowerbyi, Waagen. — tabulata, sp. nov. 



