148 W. H. Sudledon — On the TorlisJiire Oolites. 



or Dogger. His type specimen belonged to Bean, and should be 

 either at York or in the British Museum. I have not seen it. 



It is perhaps of more importance to know how far this rather 

 abundant form is related to Alaria harmis, Desl., which that author 

 describes as not uncommon in the Inferior Oolite of Normandy, 

 though rare in the Great Oolite of that country. In 1850 Morris and 

 Lycett (Grt. Ool. Moll. pp. 16 and 18, pi. iii. figs. 2 and 5) described 

 Al. hamus from the Great Oolite of Minchinhampton, and Al. 

 FMlUpsii from the " Great Oolite " of Scarborough, pointing out 

 what they conceived to be the differences. But Piette {op. cit. p. 

 46) says that these authors have wrongl}'^ identified Deslongchamps' 

 species ; and, as far as I can understand the point without having 

 actually seen Deslongchamps' Inferior Oolite types, the accusation is 

 not unfounded. Moreover, at page 111, these authors say, "The York- 

 shire shell appears to be identical with Eostellaria hamus, var. /3 of 

 M. Deslongchamps, from the Great Oolite of Eanville," and Morris 

 indorses this view of the case in his Catalogue. Yet this identifica- 

 tion with var. yQ is not a happy one, since the Eanville type, 

 which is in the Tesson Collection at the British Museum, has the 

 upper or major keel of the body-whorl nodular (carina . . . nodulosa, 

 iiodulis parvis, crebris), whereas the Yorkshire specimens are like 

 var. a from the Normandy Inf. Oolite, where the keel is plain. 

 Hence Morris and Lycett were mistaken on both points. 



Description. — Specimen from the Dogger (zone 1), Peak (Blue 

 Wyke). Leckenby Collection. PI. VI. Figs. 3 and 3a. 



Length! 22 millimetres. 



Width of last whorl to length of shell 41 : 100. 



Approximate spiral angle 26°. 



Shell elongate, turrited. Whorls about 9 or 10 (the 3 anterior 

 ones alone are perfect). The visible whorls of the spire are angular, 

 with a prominent keel, which is central. The posterior half of the 

 keel slopes outwards, whilst the anterior portion is nearly straight. 

 These whorls are ornamented by numerous fine spiral lines of nearly 

 equal strength, though they become rather finer on the body-whorl. 

 About 10 short stout longitudinal costulse are arranged in a circlet, 

 chiefly on the anterior half of each whorl (medio angulato-nodosis, 

 nodulis plus minusve crebris, Desl.). In the penult these costulas are 

 little more than large tubercles, but in the higher whorls they are 

 relatively longer and slope slightly from right to left. The bodj'- 

 whorl seems to have suffered from exposure, whereby the spiral 

 lines are almost effaced, but it is gibbose and bicarinate, the upper 

 keel being much the stronger. Both keels are plain, though it is 

 not improbable that a spine existed where there is a partial break 

 in the continuity. 



As this specimen is involved in matrix, the digitation that sprang 

 from the upper keel is only just visible, and beyond this nothing 



1 In the following measurements of Alaria "length " means the full length of the 

 shell restored, without the canal. In other respects no great accuracy is claimed, 

 since all the specimens are more or less mutilated, and for the most part enveloped in 

 matrix. 



