190 GASTEROPODA OF THE INFERIOR OOLITE. 



later whorls the section is more inclined to be quadrate, giving evidence of the 

 absence of preparations for the anterior canal. 



Varieties. — A variety from near Beaminster (fig. 7) is rather more squat 

 in figure, has the keel somewhat lower down, and does not expose the rudi- 

 mentary lower keel in the penult to such an extent. Another variety (fig. 8), 

 from the irony-nodule bed of the Murchisonse-zone in Burton Cliff, differs in an 

 exactly opposite direction, being narrower, and displaying the lower keel at a still 

 earlier stage than Ps. Etheridgii. Moreover, the crenulations on the keel, and the 

 granular zone on the posterior margin, are much more pronounced. This I 

 propose to call var. granosa, indeed it is almost worthy of being regarded as a 

 distinct species. 



Relations and Distribution. — Pseudalaria Etheridgii occurs somewhat sparingly 

 in the Sowerbyi-hed of Bradford Abbas, and has been met with on or about the 

 same horizon at Pitcombe. This species may be regarded as the type of a genus 

 which has representatives on lower as well as on higher horizons. My attention 

 has lately been called by Mr. Edward Wilson to a specimen obtained from the 

 Lias, which he regards as identical with Purpurina Patroclus, D'Orb. This well- 

 preserved fossil differs from Ps. Etheridgii chiefly in the more decided character 

 of the anterior canal, which gives to this part of the aperture an appearance not 

 unlike that of the Purpurines. 



119. Pseudalaria jugosa, Bean. No date. Plate XII, fig. 9. 



1885. " Tbochus JUGOstis," Bean MS. Hudleston, Geol. Mag., dec. iii, vol. ii, 



p. 255, pi. v, fig. 11. 



Bibliography. — It was mentioned (loc. cit.) that this could hardly be a Trochus. 

 " It has more the look of an Maria without the wing. On the other hand, it may 

 represent a shell which never had a wing." Attention was at the same time 

 directed to Turritella unicarinata, Desl. 



Description. — Shell conical, turrited ; whorls five or six ; suture well marked, 

 and situated in a hollow. The whorls of the spire are angular, and slope 

 outwards to a very prominent carina situate about two-thirds down. Keels sharp 

 and apparently plain. Faint traces of a lower keel may be noted in the whorls of 

 the spire ; body- whorl strongly bicarinate. The whole of the shell, including the 

 base, is marked by fine spiral lines. Other indications wanting. 



Relations and Distribution. — This species somewhat resembles the Beaminster 

 variety of Pseud. Etheridgii ; the deficiency of ornament may be due to conditions 

 of mineralization. Very rare in the Yorkshire Dogger. 



