UUACllIOI'OliA. Kl.i 



The Mpr/crlifT often resemble Aniiojx' in slia])e, smil in liaviii}; 

 corresnoiuling nl)S ; the ilentieuhition of the intennil niiir};m of 

 the viiives in some species may be eoinpiu'cd with the larger mar- 

 ginal processes of the latter genus. 



* Loop doubly attached. Megerlia. 



I. Mkukrlia truncata. B.M. 



S/u'// transversely oblong, or suborhienlar, with a long straight 

 hinge-line, horu-eoloured, with very fine radiating strije ; beak 

 truncated ; hinge-area flat and wide ; foramen large, ineomjilete ; 

 di'ltidiii nuMute, separate; dorsal valve nearly flat, slightly de- 

 ])ressed in front ; interior of both valves spinnlose ; loop short, 

 donljlv attached, and giving otf from its reflected portion two ad- 

 ditional i)rocesses to the central septum. Lon. G, lat. i) lines 

 (figs. 15, 16). 



List. Conch, t. 4fi2. f. 23. 



Anoniia truncata, Linn. S. N. 1152. 



Bom, Mus. US. t. 6. {. \4. 



Chemnitz, Conch. Cab. viii. 90. t. "tl . f. 701. 



Gmdin, S. N. 334.'1 



DiUw. R. S. i. p. 2!)2. 



Poli, Test. Sicil. p. l!n. t. 30. f. 16, 17- 



Pallas, Misc. Zool. t. 

 Terebratula, Lamk. E. M. t. 243. f. 2. 

 Terebratida truncata, Retz. Nov. Gen. p. 14. 



Lamk. Hist. vi. p. 247 ; ed. 2. \-ii. p. 333. 



Sow. Thes. Conch, ra. p. .354. t. 71- f- 64-67. 



De Buch, Mem. p. 66. 



Blainv. D. S. N. hii. p. 139. 



Philippi, Moll. Sicil. i. p. 95. t. 6. f. 12. 



Quenst. Handb. p. 462. t. 37. f. 10. 

 Terebratella truncata, D'Orb. Ann. Sci. Nat. 1848, viii. ]>. 66. 



t. 7. f. 11, 12, 16, 37. 

 Terebratula monstrosa, Scacchi, Oss.Zool. ii. ]>. 1. 

 Auomia disculus, Pallas, Misc. Zool. p. 184. t. 14. f. 1 (1766). 

 Terebratula (D.) disculus, Blainv. D. S. N. liii. p. 138. 

 Orthis truncata, Philippi, Sicil. ii. p. 69. 

 !Megerlia truncata, Kiny, 1850, Permian Fossils, 81. 145. 



Dav. Ann. Nat. Hist. 1852, p. 369. 

 Terebratula obUta, Michelotti, Brach. p. 4. 

 Orthis obUta, Mich. Faun. Mioc. pi. 2. f. 21. 



