CRYPTAULAX. 181 
Genus—Cryprautax, Tate, 1869, ‘Ann. and Mag. Nat. Hist.,’ ser. 4, vol. iv, 
p- 418; = Psevupocertraium, Cossmann (at least in part), 1884, ‘ L’Htage 
Bath.,’ p. 124. 
Shell elongate, pointed, with a more or less polygonal spire, ornamented with 
longitudinal ribs, which succeed each other with a twist from left to right—a feature 
more conspicuous in some species than in others. Suture wide, columella short, 
aperture suborbicular to ovate, with little or no anterior canal. Peristone entire, 
and broadly reflexed on the inner side—a shallow, oblique, posterior canal in the angle 
formed by the body-whorl and outer lip. (Tate’s diagnosis somewhat modified.) 
Type, C. tortilis, H. and D. 
Cossmann (op. cit.) gives a somewhat similar diagnosis as regards the shell, 
but does not mention the concealed posterior canal as one of the features of his 
genus, Pseudocerithium, the type of which he takes to be Cerithium undulatum, 
Quenst. 
It may be that Oryptaulaw and Pseudocerithium are not exactly synonyms, 
though M. Cossmann is now disposed to regard them as such. If we allow that 
they are synonyms, the genus Cryptaulaz certainly will cover shells which present 
considerable differences. 
Oryptaulae occurs most abundantly in the Parkinsoni-zone, and is mainly 
confined to No. 1 District. No species, either from the Lincolnshire Limestone 
or from Yorkshire, has hitherto come under my notice. 
111. Crypravsax scopma, Deslongchamps, 1842. Plate XI, fig. 10. 
1842. CrEriruivm scosina, Desl. Mém. Soc. Linn. Norm., vol. vii, p. 196, pl. x, 
fig. 49. 
1867. _ varicosuM, Desi. Moore, Middle and Upper Lias, p. 83, pl. iv, 
fig. 15. 
1869. CrypravLax scopina, Des?. Tate, Ann. Mag. N. H., ser. 4, vol. iv, p. 418. 
Bibliography, §c.—Originally described from a single specimen in the Upper 
Lias of Fontaine-Etoupefour. Moore obtained four examples from the highest 
horizon of the Ilminster Upper Lias ; these he referred inadvertently to Cerithium 
varicosum, Desl. Tate pointed out the mistake. 
Description : 
Leneth : : : . 17 mm. 
Width : : . - 3 oomms 
Spiral angle ; : : SB 
