ACT^ONINA. 471 



wliorl (fig. 16 a), but are well marked where the anterior compression commences. 

 Aperture ovate-elongate with a thin straight outer lip and a smooth columella. 



Relations and Distribution. — Differs from Actseonina pulla in the fineness of 

 the striations, though, if we accept the view of Stoliczka, this may be somewhat a 

 matter of preservation. Resembles Actseonina sparsisulcata, d'Orbigny (' Terr. 

 Jur.,' ii, p. 166, pi, 285, figs. 14 and 15). This form occurs in the Lincolnshire 

 Limestone at Weldon, in the Parlcinsoni-zone of Burton Bradstock, and in the 

 Cadomensis-hed at Oborne. 



Since I do not venture to constitute this as a distinct species, it may be 

 regarded as a possible variety of Actseonina pulla. 



417. AcT^ONiNA (Steiact^onina) tenuisteiata, sp. nov. Plate XLII. figs. 18, 19, 



19 ft. 



1885. AcT^ONiNA HUMEBALis, Phillips, striated variety. Hudleston, Geol. Mag., 



1885, p. 202, pi. V, 

 fig. 3. 

 Cf. also AcT^ONiNA. Saethacensis, d'Orligny. Terr. Jur., vol. ii, p. 1G7, pi. cclxxxvi, 



figs. 1 and 2. 



Description : 



Height . . . . .12 mm. 



Body whorl to total height . . . 75 : 100. 



Spiral angle .... 60°. 



Shell cylindro-conical ; the spire occupies about one fourth of the total height, 

 and consists of five or six whorls, which are cylindrical with tabulate posterior 

 margin, except towards the very sharp apex, where they are slightly convex. The 

 entire shell is pervaded by fine and close striato-punctate ornament. There is a 

 strongly impressed line on the posterior margin of the whorls, and a somewhat 

 finer line on the flat area between the margin and the suture. The body-whorl is 

 a narrow cylinder much compressed anteriorly ; aperture ovate-elongate with a 

 smooth columella. 



Relations and Distribution. — This may be regarded as a narrow representative 

 of Actseonina Sarthacensis on a lower horizon. (Oossmann says that A. Sarthacensis 

 is really a Bathonian species, and not Bajocian as represented by d'Orbigny.) On 

 the other hand, if we accept the suggestion of Stoliczka as regards striation in the 

 Tornatellidge, Actseonina tenuistriata. may be nothing more than a different mineral 

 condition of Actseonina Jiumeralis. This was the view I took in 1885. There are, 

 however, certain slight differences of shape which favour the notion of their being 

 distinct species. 



