150 W. H. Sudleston — On the YorJcs/iire Oolites. 



spiral lines are sharp, rather wide apart, and somewhat unequal. 

 The longitudinals consist of about 9 stoutish ribs, which have a 

 tendency to be spinulose here and there. These are feebly developed 

 on the upper part of the whorls, but strong in the anterior portion, 

 though scarcely reaching the suture : they have a slight inclination 

 from right to left. 



Body-whorl moderately large in proportion to the rest of the spire, 

 rounded, and divided nearly equally by a plain keel. The spiral 

 lines are continued in the upper part of the body-whorl, but have 

 left only slight traces in the anterior portion. The wing has one 

 lateral digitation (broken off), though both this and the canal were 

 probably rather short. 



Another specimen. — Same horizon and locality. Bean Collection, 

 British Museum. Figs. 2, 2a. 



Length 25 millimetres. 



"Width of last whorl to length of shell 45 : 100. 



Approximate spiral angle 30°. 



In this fragment the character of the ornamentation is unusually well 

 shown; there are 5 whorls preserved. Whilst the shell itself is more 

 robust, the spiral striee are finer and more numerous than in the other 

 specimen ; the longitudinal cost^ are also very prominent and some- 

 what longer, with a marked inclination from left to right. The 

 peculiarities of the body- whorl are almost the same, only one keel 

 being visible, and that quite plain. 



Belations and Distribution. — The two specimens figured are the 

 only ones known to me. From Al. PMUipsii this form differs in the 

 smoother outline of all the whorls, and notably of the body-whorl, 

 in the greater length of the longitudinal costulee, and above all in 

 the absence of any clearly developed anterior keel in the body-whorl. 



There can be very little doubt that the above three forms, whether 

 we call them species or varieties, were pretty closely related ; the 

 differences being such as a variable genus like Alaria would easily 

 cover. Unfortunately, when this is the case, such differences are 

 often so local as to be of little value for purposes of comparison. 



38. — Alaria pseudo-akmata, sp.n. Plate YI. Figs, 6 and 6«. 



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

 Wyke). Leckenby Collection, 



Length 26 millimetres. 



Width of last whorl to length of shell 48 : 100. 



, Approximate spiral angle 34°. 



Shell strongly turrited. The complete spire consisted probably of 

 10 whorls : portions of 7 are visible. They are extremely sharp and 

 angular in outline, the dividing carina occurring about frds down — 

 a feature which is very marked in the penultimate. Each whorl has 

 about eight short, tuberculated costulae, which are quite axial in 

 direction, and do not affect the upper part of the whorls. The con- 

 dition of the shell does not permit of any certainty as to the chai'acter 

 of the spiral lines, but they seem to have been very unequal. The 

 body-whorl is largely developed and extremely angular : it has one 



