OF CONCHOLOGT. 281 



Genus METOPTOMA, Phillips. 



Metoptoma, Phil., Geol. Yorksh. ii, p. 223, 1836. Leonh. 



and Bronn., Jahrb. p. 750, 1841. Morris, Br. foss. p. 



151, 1843. Woodw., Man. p. 155. Stoliczka, Pal. In- 



dica, ii, p. 324. Eichw., Leth. Ross, i, p. 1098. 

 Not DeslongcJiampsia, as per Chenu, Man. de Conchyl. i, p. 



376 ; nor Patella, lb. i, p. 375, fig. 2281. 



Shell patelliform, scar horseshoe shaped ; apex subcentral, 

 shell truncate behind the apex, with the posterior margin broadly 

 emarginate or waved, and the anterior slope the longest. 



Type M. pileus, Phil., 1, c. p. 224, pi. xiv, f. 7. Carb. lime 

 stone, Great Britain. 



This genus, characterized by the extraordinary jjosterior trun- 

 cation, is only known from the older rocks in a fossil state. 



Chenu wrongly places it as a synonym of Deslongchampsia, 

 McCoy, (though having eighteen years priority !) with which it 

 cannot be affiliated. His figure of Patella Solaris, de Kon., 

 represents a typical 3fetoptoma, but not the type of the genus, a 

 statement I wrongly attributed to Mr. Meek, in this Journal vol. 

 vi, p. 20. Stoliczka compares Capiilus Troscheli, Mull., from 

 the Aachen cretaceous beds, with Metoptoma, which it appears 

 to resemble. A number of the species referred by Billings (Pal. 

 Foss. Can. Geol. Survey) to this genus, are evidently not conge- 

 neric. 



LIST OF FIGURES. 

 Plate 14. 



1. Aemcea mitra, Esch. Original. 



2. " virginea, Miill. Confirmed from Loven's figure. 



3. " insessa, Hinds. Original. 



4. Collisella patina, Esch. Original, 



5. " strigatella, Cpr. Original ; a, uncinus. 



6. " pelta. Esch. Original. 



7. " asmi, M'ldd. Original; a, uncinus. 



8. " persona, Esch. Original. 



9. " mitella, Mke. Original. 



10. " spectrum, Rve. Original. 



11. " fascicularis, Mke. Original. 



12. " scabra, Rve. Original ; a, uncinus. 



13. " testiidinalis. Mull. Original. 



14. " suhrugosa, D'Orb. Original. 



15. " atrata, Cpr. Original ; a, uncinus. 



