figured in Phillips's 'Geology of Yorkshire? 411 



6. Euomphalus cristatus, Phillips (p. 225, t. 13. fig. 5). 



This fine specimen was made the subject of a distinct 

 genus, at a somewhat later date, by Mr. J. de C. Sowerby, 

 under the name of Phanerotinus. Its characters, as compared 

 with Euomphalus generally, are so anomalous that it could 

 scarcely be retained in the latter with propriety. I therefore 

 agree with Prof. Morris in the retention of the name for this 

 species at least. The shell was of considerable thickness, and 

 with its shelly outgrowths must have presented a handsome 

 appearance. It is the 



Euontphalus cristatus, Phill. loc. cit. 



Phanerotinus cristatus, J. de. C. Sow. Min. Conch. 1843, vii. p. 29, t. 024. 



figs ; 1, 2 ; Morris, Cat. Brit. Foss. 1854, ed. 2, p. 267. 

 Eccyliomphalus cristatus, M'Coy, Brit. Pal. Foss. 1853, fasc. 3, p. 542. 



7. Cirrus acutus, J. Sowerby (Phillips, p. 225, t. 13. fig. 12). 



As represented by Phillips the figured specimen is only a 

 portion of a larger one ; the position, however, in which it is 

 placed is rather misleading. I cannot for a single moment 

 agree with Prof, de Koninck in his statement that with the 

 exception of the height of the spire this species has nearly all 

 the characters of E. pentangulatus. In the first place, Cirrus 

 acutus possesses no angulation on the underside of the body- 

 whorl, which is a well-marked feature in E. pentangulatus ; 

 secondly, in the former the portion of the shell above the 

 angulation of the body -whorl, on the upper surface, is flat or 

 concavely bent upwards, whilst in the latter species the cor- 

 responding portion of the body or last-formed whorl is concave 

 inwards and downwards. Now, if fragments of these shells 

 are met with, these features would give to them a very great 

 and marked difference. Further, this is repeated in each 

 whorl of E. pentangulatus, making it therefore constant ; 

 whereas in Cirrus acutus the angularity of the body-whorl is 

 quite lost in the upper ones, they becoming simply rounded. 

 On the other hand, I think it more than probable that Prof, 

 de Koninck is correct in regarding Phillips's Cirrus pentago- 

 nalis as only the young form of C. acutus. A much nearer 

 relative of the latter than E. pentangulatus is C. tabulates, 

 Phillips, as pointed out by Prof. M'Coy, especially in the 

 young state of the last named, although the whorls in C. acutus 

 have not the depressed, truncated, and markedly rectangular 

 appearance of C. tabulatus, which will at once separate the 

 two. It is the 



Cirrus acutus, J. Sow. Min. Conch. 1816, ii. p. 43, t. 141. fig. 1 (2 figs.). 



Cirrus acutus, Phillips, loc. cit. 



Cirrus pentflgonalis, id. ibid. p. 226, t. 13. fig. 8. 



