OP CONCHOLOGY. 



129 



Genus MEGERLIA, King * 



MegerUa, King, Perm. Foss. 81, 145, 1850. Dav., An. Nat. 

 Hist. 1852, p. 369. Ibid., 1861, p. 38. Woodw., Rec. 

 and Foss. Shells, p. 219. Rve., Conch. Icon. pi. xi. 

 Journ. de Conchyl. 1861, p. 133. Dav., Int. Clas. Brit. 

 Brach. 1851-4, p. 68. H. and A. Adams, Gen. Rec. 

 Moll, ii, p. 578. Jeffreys, Brit. Conch, vol ii, p. 22. 

 Megej'lea, Dav., Intr. a I'Hist. nat. des. Brach. vivent et fos- 

 siles Mem. Lin. Soc. de Normandie, 1856, p. 129. Chenu, 

 Man. de Conchyliol. vol. ii, p. 205. 

 Megathyris, D'Orb. (part), M. ohlita. 

 Orthis, Philippi, Moll. Sic. ii, p. 67. Michelotti, Faun. Mio. 



pi. ii, fig. 21. 

 Terehratella. D'Orb. An. Sci. Nat. 1848, p. QQ (part). 

 Anomia, Linn., Pallas, (fee. 

 Terehratula, Auctorum. 



Shell transversely oblong with a straight wide hinge line, dis- 

 tinct area and large incomplete foramen. Externally striate, 

 internally pustulose, somewhat pearly. 



Loop resembling that of Ismenia, but with the lateral loops 

 filled up with calcareous matter in the adult, forming two spatu- 

 late processes. 



Brachia behind the mouth, furnished with two lateral lobes 

 and a conspicuous median spiral lobe. 



This genus approaches Ismenia in the form of the loop, but 

 otherwise is totally unlike that group, which is more properly 

 placed among the Terehratellce. 



Fig. 14. 



Megerlia truncata, ^ nat. size, a, haemal valve with the animal ; b, same 

 with animal removed, showing the apophyses. 



* This is very close to MegerJea, Robineau-Desvoidy, Essai sur les 

 Myodaires, 1830, a genus of Diptera. In fact, when properly spelled, 

 they are identical and were named for the same individual. I do not 

 know whether Desvoidy's genus still stands, but in case it does, Megerlia, 

 King, will have to be dropped, as the dipterous genus has twenty years' 

 priority. 



Not«. — A letter from the eminent dipterologist. Baron Osten Sacken, 

 informs me that Desvoidy's genus has not been adopted by entiimolo- 

 gists, and therefore we are at liberty to retain the old, familiar and 

 well established name of Megerlia for the present genus. 



