figured in Phillips's 'Geology of Yorkshire.'' 293 



it ; however, I think it is desirable a series of specimens 

 should be examined before any conclusive result can be arrived 

 at as to the value of this species. It is the 



Metoptoma oblonga, Phillips, loc. cit. 



? Patella oblonga, De Koninck, Animaux Fossiles, p. 329, t. 23. 



fig. 6, a, b. 

 Metoptoma oblonga, Morris, Cat. Brit. Foss. 1854, 2nd ed. p. 258. 



Metoptoma sulcata, Phillips (p. 224, t. 14. fig. 11). 



A small and imperfect shell. The ornament is exactly 

 similar to that of M. imbricata ; and, with the present material 

 before me, I should not be inclined to do more than recognize 

 it as a variety of the latter. It is the 



Metoptoma sulcata, Phillips, loc. cit. ; Morris, Cat. Brit. Foss. 1854, 

 2nd ed. p. 258. 



On the Genus Metoptoma, Phillips. — This genus was de- 

 scribed in 1836 by the late Prof. Phillips for patelliform Carbo- 

 niferous shells having the posterior end (or that under the 

 apex) truncated. It was not adopted by Prof, de Koninck in 

 the body of his work on the Belgian fossils, but was after- 

 wards admitted, to some extent, in the supplement to that 

 work, in consequence of the discovery of the muscular scars 

 on the interior surface of the shells of M. pileus, Phill., and 

 M. Solaris, De Kon. ; good examples of these are now in the 

 British-Museum collection. In the two species just men- 

 tioned Prof, de Koninck describes the scars as horseshoe- 

 shaped, placed on the posterior side of the shell, with their 

 dilated pyriform ends directed towards the front. 



Neither De Koninck nor M'Coy mention the fact that 

 Phillips had already figured the muscular impressions in M. 

 oblonga, although he failed to make any note of their signifi- 

 cance ; not so, however, those discriminating paleontologists 

 Messrs. Meek and Worthen*, who draw special attention to 

 this figure in the ' Geology of Yorkshire.' 



Baron de Kyckholt t refers Metoptoma to the genus Helcion, 

 De Montfort. This, however, simply arises from a misappre- 

 hension of the characters of the former, because the forms from 

 the Carboniferous rocks of Belgium ascribed by De Kyckholt 

 to Helcion bear no resemblance to those upon which Phillips 

 established his Metoptoma, beyond all being more or less 

 conical patelloid shells. 



Prof. Hall has suggested % that the Metoptomos of Phillips 



* Proc. Acad. Nat. Sci. Philadel. 1866, p. 266. 



t Mem. Couronn6s Acad. R. Belg. 1852, xxiv. p. 56. 



X Twenty-third Ann. Report State Mus. N. York, p. 242. 



