360 GASTEROPODA OF THE INFERIOR OOLITE. 



Bibliography, Src. — In adopting the above name I wish to indicate that a certain 

 form is widely, though not abundantly, spread throughout the Lower Oolites, which 

 undoubtedly belongs to the group of which the Corallian species, D. funata, Miinst., 

 is a member, but yet is not the same species. The question calling for immediate 

 decision is, what shall we call this fossil ? On the whole, it seems to me that 

 Turbo Hamptonensis may be made to cover the ground with the reserve, " Inferior 

 Oolite variety." 



Description. — Height 11 mm., width 10 mm., but variable in this respect ; 

 spiral angle 65°. Shell conical, moderately umbilicated. Spiral angle fairly 

 regular, but with a flattened apex. Number of whorls usually five, those at the 

 apex smooth, the others richly ornamented with tuberculated spiral bands, about 

 three in number on the penult and antepenult ; sutures wide and in some cases 

 almost gaping. 



The body-whorl is about half the entire height, subventricose, and carries four 

 tuberculated spirals on the flank, which is in some specimens somewhat bicarinated. 

 Base rounded and studded with tuberculated spirals, of which the lowest, dis- 

 tinguished by larger granulations, forms a prominent demilune at the margin of 

 the umbilical cavity. The aperture is subcircular, the outer lip thin and 

 crenulated ; the inner lip is slightly angular towards the columellar extremity, 

 where there is a sort of thickening. 



Relations and Distribution. — The above diagnosis represents a more vigorous 

 form than Turbo Hamptonensis, which was described from a single specimen in the 

 Great Oolite of Minchinhampton. A still smaller variety is Turbo Burtonensis, from 

 the Forest-Marble. Not always to be distinguished from Monodonta Lyelli, 

 and intimately connected with Turbo Davoustii, which is probably nothing more 

 than an exaggerated and squamose variety. 



Rare in Dorset ; occurs at different places and on different horizons in the 

 Cotteswolds. Some of the most characteristic specimens are from the neighbour- 

 hood of Hook Norton, where it is not always easy to distinguish it from Monodonta 

 Lyelli. Varieties from the Dogger and Cornbrash of Yorkshire have been figured 

 by me in the { Geological Magazine ' (vol. cit.). 



296. Tuebo (Delphinula) Davodstii, d'Orbigny, 1850. Plate XXX, fig. 7; and 



var. Lindonensis, fig. 6. 



1850. Tuebo Davoustii, d'Orbigny. Prod., i. p. 266. 



1852. — — — Terr. Jur., vol. ii, p. 344, pi. cccxxxi, figs. 



7—10. 



Bibliography, 8fc. — This is perhaps the form recognised by Lycett (' Proc. 

 Cotteswold Nat. Club,' vol. i, p. 71) as Delphinula funata, Goldfuss, and also by 







