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. Eostellabia trifida, Bean, MS. Phillips G. T., p. 109, pi. v 



fig. 14. 

 Compare also 



1836. Fusus cuevicauda, Roem. Ool. Geb., p. 140, pi. xi, fig. 6. 



1837. Chenopus Philippi, Bunker and Koch. Beitr., p. 34, pi. ii, fig. 13. 

 1844. Kostellaiua bicahinata, Munst. Groldfuss, Pet., iii, p. 15, pi. 170, 1. 

 1867. Alabia cochleata, Quenstedt. Piette, Cont. de la Pal. Franc., p. 110, 



pi. xxii, figs. 1 — 6. 



The trifida-growp stands out tolerably distinct from all the others. In this 

 country its earliest representative, Al. Lorieri, var. gracilis, appeared in the 

 Murchisonce-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. Alaria Lorieri, D'Orbigny, 1850. Plate VI, figs. 6 a, 6 b, 6 c, 6d; 6 a', 



6' b ; 6" a. 



1850. Ptekoceba Lobiebi, B'Orbiynij. Prod., i, p. 270. 



1867. Alabia — — Piette, Cont. de la Pal. Franc., p. 32; 



see plates ii, iii, iv, and vi. 

 Compare also 



1842. Eostellabia tbifida, Phillips. Deslongchamps, Mem. Soc. Linn. Norm., 



vol. vii, p. 171, pi. ix, ? figs. 27, 28. 



1869. Chenopus Philippi, Bunker and Koch. Brauns, Mittlere Jura, p. 170. 



1873. Alaria Lobiebi, B'Orligny. Tawney, Dundry Gasteropoda, p. 13. 



Bibliography, Sfc. — 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 



