156 W. H. Hudleston—On the Yorkshire Oolites. 



Genus Trochotoma, Deslongcliamps, 1842. 

 This genus, the authorship of which was claimed both hj Lycett 

 and Deslongchanips (see Corallian Gasteropoda, Geol. Mag. 1881, 

 p. 61, Sep. meui.), seems to have been first noted in England on the 

 horizon of the Inferior Oolite, whilst in Normandy it occurs also in 

 the Lias. It was classed by S. P. Woodward along with Fhurotomaria 

 in the family of the Ear shells ; but if we are to accept the family 

 Pleurotomuridm, the genus Trochotoma would seem to belong to that 

 family, though perhaps nearer to the Haliotids than Pleurotomaria, a 

 genus of higlr antiquity, 

 83.— Trochotoma calix, Phillips, 1829. PI. IV. Pigs. 6, Qa, Qb. 



1829, 1835. Solarium calix, Bean, MS. Phillips, G.Y. p. 129, pi. xi. fig. 30. 

 1842. Trochotoma gradits, Deslougchamps, Mem. Soc. Linn. Norm. vii. p. 106, 



pi. 8, figs. 4-7. tipper Lias. 

 1852. Ditremaria bicarinata, D'Orbigny. Terr. Jurass. p. 380, pi. 340, figs. 8-11. 



Middle Lias. 

 1854. Trochotoma calyx, Phil. Morris, Cat. p. 280. 

 1873. Trochoto7na c/radus, Beslong. Tawney, Dundry Gasteropoda, p. 45. 

 1875. Trochotoma calyx, Phillips. G.Y. 3rd edition, p. 259, pi. xi. fig. 30. 



JSTon Pleurotomaria calix, D'Orbigny. Terr. Jurass. p. 476, pi. 383, figs. 6, 7. 



Compare also, 



1842. Trochotoma affinis, Desl. vol. cit. pi. 8, figs. 8-10. 



1857. Trochotoma carinata, Lycett. Cotteswold Hills, pi. 4, fig. 5. 



Bibliography, etc. — The type of Solarium calix should be at York, 



Having adopted the principle of only admitting species which 1 know to have been 

 procured in Yorkshire, these are not enumerated, but I give the references and 

 bibliography below. 



I. 1821. Trochus bicarinatus, Sowerby, M.C. t. 221, fig. 2. 



1829 and 1835. Trochus bicarinatus, Phillips, G.Y. at p. 107, as from the L.C.G. 



at p. 165 as from the CO. , 



1849. Pleurotomaria bicarinata, Sow. D'Orb. Prod. 1, p. 356, Et. Oxf. Not 



noted in the Terr. Jurass. 

 1854. Pleurotomaria bicarinata. Sow. Morris, Cat. p. 271. 



The type may be seen in the collection of Sowerby's types at the British Museum. 

 Along with it is a card originally labelled ^^ Trochus tiara,'' but corrected „to 

 " bicarinatus, M.C. non Lam." The word " Marcham " is lightly written in pencil 

 upon the fossil itself. 



The specimen is faithfully represented in Sowerby's figure, who says of its origin, 

 *' preserved in marl mixed with green sand, found in Marcham Field, near Oxford." 

 There can be no mistake as to the form : I have never seen anything like it in any 

 of the collections from Yorkshire. The most curious fact is that Morris quotes it 

 from the CO. and CG. of Yorkshire, but not from Marcham. Hence he probably 

 had doubts about its having been found there. The matrix and status are certainly 

 not suggestive of the Calc. Grit or Coral Rag of that locality. 



Apart from any question of its occurring in Yorkshire, the uncertainty respecting 

 such a type will give great trouble to any one undertaking to review the British 

 Jurassic Pleurotomarice. 



II. 1829-1835. Cirrus cingulatus, Bean. Phillips, G.Y. p. 107, pi. iv. fig. 28. 



Calc. Grit. 

 1849, Turbo suh-cingulatus, WOxh. Prod. i. p. 355, Et. Oxf. Not noted in 



the Terr. Jurass. 

 1854. Cirrus ? cingulatus, MoiT. Cat p. 243. 

 Phillips described it as rare in Mr. Bean's cabinet. The specimen has disappeared, 

 and it is difficult to say Avhat it represented. Nothing of tlie kind is to be found in 

 existing collections. Compare Solarium Sarthaceme, D'Orb, T. J. pi. 321, 



