132 GASTEROPODA OF 'THE INFERIOR OOLITE. 
by no means clear to me that the changes of form are coincident with change of 
horizon only, or that the differences which separate Al. Lorieri from Al. cochleata 
or Al. trifida are really of biological import. Piette seems to have more faith in 
the existence of these differences, and it is quite possible that the superior con- 
dition of the French fossils has justified the separation. In addition to any 
references which may be given the following general references should be noted : 
1829 and 1835. Rosrernarta rriripa, Bean, MS. Phillips G. Y., p. 109, pl. v 
fig. 14. 
Compare also 
1836. Fusus curvicaupa, Roem. Ool. Geb., p. 140, pl. xi, fig. 6. 
1837. Curnopus Puiiipri, Dunker and Koch. Beitr., p. 34, pl. ii, fig. 13. 
1844. RosreLuarta Brcartnata, Miinst. Goldfuss, Pet., iii, joo as jal alyAO), a 
1867. AtariIa cocuiEata, Quenstedt. Piette, Cont. de la Pal. Franc., p. 110, 
pl. xxii, figs. 1—6. 
The trifida-group stands out tolerably distinct from all the others. In this 
country its earliest representative, Al. Lorieri, var. gracilis, appeared in the 
Murchisone-zone of the Cotteswolds. No traces of it are known to me in the 
Yorkshire Dogger, nor yet in the Lower Division of the Inferior Oolite in 
Dorsetshire. 
53. Atania Loriert, D’Orbigny, 1850. Plate VI, figs. 64, 6b, 6c, 6d; 6a, 
(5) (OGY 
1850. Prrrocera Lorrert, D’Orbiyny. Prod., i, p- 270. 
1867. Aanrta — — Piette, Cont. de la Pal. Fran¢., p. 32; 
see plates 1, iil, iv, and vi. 
Compare also 
1842. RosreLrarta rriripa, Phillips. Deslongchamps, Mém. Soe. Linn. Norm., 
vol. vii, p. 171, pl. ix, ? figs. 27, 28. 
1869. Curnopus Pritrprt, Dunker and Koch. Brauns, Mittlere Jura, p- 170. 
1873. Atarta Lorteni, D’Orbigny. Tawney, Dundry Gasteropoda, p. 13. 
Bibliography, §c.—Deslongchamps, who applied the name “ trifida” to all 
forms of the group from the Lias to the Kimeridge Clay, traced the species back 
as far as the Upper Lias of Fontaine-Etoupe-Four. But I cannot find in Piette’s 
work any allusion to the hamicaudes having been represented in the Lias. 
The following is D’Orbigny’s description of “ Pterocera”? Lorieri. “ A small 
species near to Pterocera (Chenopus) Philippi, but much more elongate and 
slender ; whorls strongly carinated, finely striated spirally.”” He does not mention 
any localities in Normandy but refers to the Department of the Sarthe. Piette 
