W. H. Sudleston — On the Yorkshire Oolites. 149 



more can be made out of the specimen, though there is every 

 reason to suppose that the lower keel terminated at the margin as in 

 the case of Al. hamus. 



Another specimen. Fig. 4. From the Millepore Eock (zone 2). 

 Cloughton (Sycarham). Leckenby Collection. The condition 

 of this specimen forbids any close comparison, but it is fairly 

 similar to the one above described, more especially when we bear 

 in mind the difference of the matrix.. This may be taken as re- 

 presenting the general appearance of fairly preserved specimens 

 of Alaria Fhillipsii from the Millepore Eock and Scarborough 

 Limestone. 



Relations and Distribution. — These may be inferred from what has 

 been said under the head of bibliography. The typical Al. hamus 

 would seem to be a somewhat more robust shell, with rather a 

 wider spiral angle, and with the tuberculations that form the circlet 

 round each whorl more closely set. Common to all three zones of 

 the Inferior Oolite in Yorkshire. 



Description of a spinulose variety. — Specimen from the Dogger 

 (zone 1), probably from the Peak. My collection. Fig. 5, magnified 

 twice. 



Length » 23 millimetres. 



Width of last whorl to length of shell 38 : 100. 



Approximate spiral angle 30°. 



Six whorls are preserved. They are slightly less angular than in 

 Al. Phillipsii, and the outline produced by the longitudinal costul^ is 

 not quite so much that of a mural circlet. Moreover, in the upper 

 whorls, the costulse extend very nearly from suture to suture, though 

 this is not the case in the penultimate. But the chief difference 

 occurs in the body-whorl, which is not quite so gibbose as in the 

 more typical form, though this appearance is partly due to scraping; 

 the upper keel is spinulose, instead of being plain. The other differ- 

 ences shown in the figure are in a great measure the result of status. 



Relations and Distribntion. — It is presumed that there is no con- 

 siderable difference between this and more typical forms of Al. 

 Phillipsii ; but as all the specimens are more or less mutilated, some- 

 thing must be left to conjecture. Only two specimens of this variety 

 are known to me, viz. the one figured and the one previously men- 

 tioned, in a foot-note, as being in the collection of Sowerby's types. 

 Both are from the Dogger. 



37. — Alaria unicarinata, sp.n. Plate VI. Figs. 1, 2, 2a. 



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

 Wyke). York Museum. 



Length 22 millimetres. 



Width of last whorl to length of shell 44 : 100. 



Mean spiral angle 30°. 



Shell turrited. The complete spire would consist of about 9 or 

 10 whorls : 7 are visible. The apical whorls are apparently but 

 slightly ornamented, and the very earliest ones were probably quite 

 smooth. The other whorls are full, the penult and antepenult being 

 subangular, but without any very strongly developed carina. The 



