W. H. Hudleston — On the Yorkshire Oolites. 151 



large median keel which sujjported one or two immense spines. 

 Although some of the spiral lines on the body-whorl are sti-onger 

 than others, there is nothing which could fairly be called a second 

 keel. The aperture is broken away anteriorly and the outer lip 

 obscured, so that there is no absolute certainty as to the character of 

 the wing, or as to the length and shape of the canal. 



Belations and Distribution. — Probably not far from ^?ana armata, 

 M. and L. (Grt. Ool. Moll. p. 16, pi. iii. figs. 1, la), though that 

 species is described as having three carinse. On looking over a large 

 collection of these Great Oolite forms, there are several where the 

 last whorl has only one keel ; but these seem to be all immature or 

 stunted specimens — perhaps a reversion to the older type. There is 

 one other specimen of Al. pseudo-armata, now in the Jermyn Street 

 Museum : this also is from the Dogger. 



39.— Alaria bispinosa, Phillips, 1829. Plate VI. Figs. 7-10. 



1829 and 1835. Eostellaria bispinosa, Phillips, G. Y. pp. 112 and 180, pi. iv. fig. 32, 



and pi. vi. fig. 13. 

 1854. Alaria bispinosa, Phil. Morr. Cat. p. 234. 

 1875. ,, „ Phillips, G. Y. 3rd ed p. 258, pi. iv. fig. 32. 



1880. ,, „ Phil. Geol. Mag. 1880, p. 532, PL XVII. Figs. 6 a, b, c. 



BibliograpJiy, etc. — This must be regarded as a group rather than 

 as a species. In his earlier edition Phillips referred the fossil from 

 the Lower Calcareous Grit (pi. iv. fig. 13) and the fossil from the 

 Kelloway Eock (pi. vi. fig. 13) both to Bostellaria bispinosa, though 

 with a query; but in the edition of 1875, although Al. bispinosa is 

 quoted from the L. 0. G. and K. E., the fossil, depicted in 

 pi. vi. fig. 13, is referred to Al. myurus, Desk, and as coming from 

 the Cornbrash. It is perfectly true that there are representatives of 

 Al. mijurus in the Yorkshire Cornbrash, but none of them are like 

 Phillips's figure (vi. 13), which represents a wide-angled variety 

 of the bispinosa group. Both Phillips's types were provided by 

 Williamson. I have not been able to trace them. 



The question whether the fossils of the L. C. G. and K. E. should 

 be placed under the same specific designation was partly discussed 

 in the Corallian Gasteropoda^ (Geol. Mag. 1880, p. 532), and 

 allusions were made to the possible foreign equivalents. It would 

 be a hopeless task to attempt to follow the synonymy or to correlate 

 with accuracy the various modifications of this wide-spread group, 

 which has been further complicated by its having been confounded 

 with Alaria trifida, a still more widely extended species. Although 

 there are, doubtless, important differences between some specimens 

 which I have referred to Al. bispinosa, yet such difi'erences are 

 chiefly those of size ; the general character of the spire, body-whorl 

 and ornaments in all being very similai*. For Yorkshire this 

 species culminates in the Kelloway Eock, and here it is that the 



1 In describing a specimen from the L. C. G. it was suggested that it might have 

 a two-fingered wing. This I now believe to be a mistake. The chief characteristic 

 of the bispinosa group is the one lateral digitation, which together witli the canal 

 sheath or tail constitute two long processes almost at right angles to each other. 



