figured in Phillips's l Geology of Yorkshire. 1 479 



and not flattened. The spire varies in height, and the body- 

 whorl in relative convexity. C. rotundatus of Sowerby has 

 been universally regarded as a synonym of the Straparollus 

 Dionysii, De Montf. On the other hand, Prof. M'Coy has 

 to a great extent shown reasons for believing that a gradual 

 passage may be traced between S. Dionysii, Cirrus acutus, 

 PhilL, and Euomphalus anguis, M'Coy ; but Prof. Morris 

 goes further and places the last-named species as a synonym 

 of Straparollus or Euomphalus Dionysii, De Montf. The pro- 

 bability, I think, is, that they all three form varieties of an 

 extended species, of which S. Dionysii, as the first described, 

 may be taken as the type ; it is a point, however, which can 

 only be satisfactorily determined by the placing side by side 

 of a large number of examples of each. It is the 



Straparollus Dionysii, De Montfort, Conch. Syst. 1810, ii. p. 175, 



xliv e genre. 

 Cirrus rotundatus, J. Sow. Min. Conch. 1823, v. p. 3G, t. 429. figs. 1, 2 ; 



Phillips, loc. cit. 

 Euomphalus rotundatus, M'Coy, Synop. Carh. Limest. Foss. 1844, p. 37. 

 E. unguis, M'Coy, torn. cit. p. 35, t. 3. fig. 11. 

 E. Diom/sii, De Koninck, Animaux Foss. p. 438, t. 24. figs. 1-5, 8 ; 



Goldfiiss, Petr. Germ. pt. 3, p. 88, t. 191. fig. 7, a-c. 

 Straparollus Dionysii, M'Coy, Brit. Pal. Foss. 1853, fasc. 3, p. 539. 

 Euomphalus Dionysii, Morris, Cat. Brit. Foss. 1854, ed. 2, p. 247. 



11. Cirrus pileopsideus, Phillips (p. 226, t. 13. fig. 6). 



There are several examples of this shell in the Grilbertson 

 collection ; and it is in many ways a peculiar one : there is 

 one which corresponds more nearly with the figure than any 

 of the others. C. pileopsideus is discoid and much depressed, 

 and has, indeed, a very different appearance from any of the 

 other Carboniferous Euomphali. The whorls are, as described 

 by M'Coy, somewhat imbricating ; and the spire is more fre- 

 quently than not depressed below the edge of the body- 

 whorl. It is the 



Cirrus pileopsideus, Phillips, loc. cit. 



Euomphalus clausus, J. de C. Sow. Min. Conch. 1844, vii. p. 45, t. (333. 



fig. 1 (3 figs.). 

 E. pileopsideus, M'Coy, Synop. Carb. Foss. 1844, p. 37. 

 ? E. neyleclus, M'Coy, loc. cit. p. 36, t. 5. fig. 23. 

 E. pileopsideus, De Koninck, Animaux Foss. p. 437, t. 24. figs. 4, 



6, a, b. 

 Straparollus pileopsideus, M'Coy, Brit. Pal. Foss. 1853, fasc. 3, p. 540. 

 Euomphalus pileopsideus, Morris, Cat. Brit. Foss. 1854, ed. 2, p. 248. 



12. Cirrus spiralis, Phillips (p. 226, t. 13. fig. 14). 



I have not succeeded in finding a specimen which I could 

 satisfactorily consider the figured example, unless it be one 



