TURRITELLA (HAUSTATOR) RRTHBNSIS. t51 



Varietal diameters. —Agrees with the type in size, in its convex whorls, deep 

 suture and coarse sculpture, but differs from it in the greater number of its spiral 



ridges. 



Dimensions.— L. 65—75 mm. B. 18—20 mm. 



Distribution. — Not known living. 



Fossil : Waltonian Crag : Walton-on-Naze, Little Oakley. 



Miocene, Pliocene, Upper and Lower (abundant) : Italy. 



Bernard.— One of the imperfect Crag fossils here figured is from Walton, the 

 other from Oakley, where I have found several others, also imperfect. I figure 

 with them a perfect specimen from Asti. Prof. Sacco reports this variety also from 

 the Lower Pliocene of Albenga and Bordighera, where, he says, it is abundant, 

 and from the Miocene (Elveziano) of Turin, where it is rare. 



Turritella (Haustator) erthensis, sp. nov. Plate XLII, fig. 4. 



1885. Turritella triplicata, S. V. Wood, Quart. Journ. Geol. Soc, vol. xli, p. 65. 



1886. Turritella triplicata, Kendall and R. Bell, Quart, Journ. Geol. Soc., vol. xlii, p. 211. 

 1898. Turritella triplicata, A. Bell, Trans. Roy. Geol. Soc. Cornwall, vol. xii, pp. 128, 149. 



Specific Characters.— Shell large, elongate, with an expanded base; whorls 

 about 15, enlarged and ridged below, convex above, the last one-fourth the total 

 length, the base of each whorl projecting slightly beyond the one next below it; 

 spire acutely conical, regularly diminishing in size; suture conspicuous; orna- 

 mented by three prominent, clearly chiselled ridges, the lowest just above the 

 suture, the second placed closer to it than to the third, the three occupying rather 

 less than half the width of the whorls, the upper or concave part of which is 

 covered with fine irregular thread-like lines; base rounded, obtusely ungulate, 

 finely and spirally ridged. 



Dimensions.— L. 60—70 mm. B. 18 mm. 



Distribution. — Not known living. 

 Fossil : St. Erth. 



Remarks.— As already stated, a number of the large Turritellas of the Anglo- 

 Belgian basin have been regarded, under the influence of views formerly prevailing, 

 to be varieties of the T. incrassata of Sowerby or of its supposed equivalent, the 

 Turbo triplicates of Brocchi. It is true that many of them agree generally in form, 

 but they differ in sculpture. It is on the latter feature, therefore, we must chiefly 

 depend for the identification of our fossils. Guided by this principle, it will be 

 seen, I think, that several of the Crag Turritellas hitherto regarded as varietal, 

 may be either associated with certain species believed by foreign authorities to be 

 specifically distinct, or may be considered as forms hitherto unrecorded from our 

 deposits which deserve recognition. The present fossil belongs, I think, to the 



