TURBO. 361 



Witchell (' Geology of Stroud,' p. 51) as a fossil of the Oolite-Marl under the same 

 name. It belongs to the same group, no doubt, and has another relative in Turbo 

 segregatus, H. and D. (' Foss. Mont.-Bellay,' p. 57, pi. ii, fig. 10). N.B.— 

 Hitherto I have always quoted D. funata as a fossil of the Inferior Oolite in the 

 Cotteswolds on the authority of Lycett and Witchell, but it seems that Turbo or 

 Delphinula Davoustii is more suitable. 



Description : 



Height . . . . .13 mm. 



Width . . . . .14 mm. 



Spiral angle . . . . .75°. 



The description given by d'Orbigny is sufficiently near to permit of an 

 approximate identification, although there are some differences of detail. 

 T. Davoustii may be regarded as a wide-angled and spinulose relative of 

 T. Hamptonensis. It is especially characterised by tuberculations which have 

 semilunar pits of varying depth on the anterior side (a feature also of D.fuuata, 

 Goldf., and of Turbo [Delphinula] faniculatus, Phil.). The character of the base and 

 aperture is also the same, except that the tuberculations are far more vigorous. 



The best specimens are from Bradford Abbas, presumably from the higher 

 zones ; it is also found at Horton Hill in the Parkinsoni- zone, but the specimens 

 are inferior. There are also, in all probability, inferior specimens on other horizons 

 and in other localities of the Cotteswolds. 



Variety Lindonensis (fig. 6). 



Description : 



Height . . • • .11 mm. 



Width . . . • -13 mm. 



Spiral angle . 80°. 



Shell turbinate, moderately umbilicated. The spire is convex and irregular, 

 with a gaping suture, especially pronounced in the last whorl. Apex obtuse; 

 number of whorls about four, angular and subtabulate, the whole shell being 

 conspicuously muricated ; penult ornamented by three or four rows of spinous 

 tubercles. 



The body-whorl is somewhat bicarinate, and has on the flank three rows of 

 very spinous tubercles, hollowed anteriorly ; the middle row, which is situate at 

 the posterior angle, carries the largest spines. Base rounded, and ornamented with 

 four or five rows of smaller tubercles. Umbilicus and aperture as in T. Davoustii. 



Of all the members of the group known to occur in the Inferior Oolite, the 

 var. Lindonensis has perhaps the most considerable resemblance to the Corallian 



