47 

 ifletatzefiia, Quenstedt. Spiriferidcc. 1871. 



Petref. Dentschl. ii, p. 522; Atlas, pi. 54, f. 58-61. Typo Spirifcr 

 mcdianus, Quoust. 1. c. Handb. Petr. 1851, p. 482, t. 38, f. 33. (Lias.) 



HerBsta, Suess. Spiriferidw. 1 85 1 . 



Jahrb. K. K. Geol. Eeichs. ii, part iv, pp. 150, 160. Type M. herculea, 

 Barrande, Brach. Sil. Bohm. t. 14, f. 1, (Sil.); fide Dav. 1856, pi. ix, f. 

 32-35. Cbenu, Man. ii, p. 217, f. 1112, 1862. 



Davidson, 385G, iuchides Atrypa tumida, Dalm., among 

 the types of Meruta, but it appears (1861) not to be con- 

 geneuic, and is type of 3IerisfeUa, Hall, 1861; not of Hall, 

 1859 or 1862. Billings, Ann. Mag. Nat. Hist, xx, p. 233 et 

 seq., proposes to retain for (1) Athyris, M'Coy, Atrijpa tumida 

 as type, as has been done by Davidson in 1853. In 1852 

 (not 1844), M'Coy had included this sp. in Athyris. He 

 would preserve (2) Spirigera, D'Orbigiiy, with S. concentrica, 

 as type, like Davidson in 1853. Lastly, he would separate 

 (as above) A. tumida from Meristu, leaving M. lierculea, Barr., 

 as type. This cannot be adopted. The laws of nomencla- 

 ture being framed to exclude doubt in every practicable case, 

 it cannot be admitted that a type may be selected for a 

 genus which the author in his original construction of the 

 genus did not specifically include in it. Any other course 

 would open the door to a host of misconceptions. Therefore, 

 Billings's proposition cannot be entertained : 



First, because A. tumida was not included by M'Coy in 

 his original description and list of Athyrides; 



Secondly, because Sjnrigera, founded on what was prop- 

 erly taken to be M'Coy's type of 1844, was avowedly intended 

 to supersede Athyris as an ineligible name; though, in the 

 latter case, Scminula or Actinoconchus would have had prior 

 claims for adoption ; 



Lastly, because Hall, in 1860, had already made tumida 

 the type, or included it among his types of Meristella, posi- 

 tively characterized for the first time in that year. 



There is therefore no reason for disturbing Mr. Davidson's 

 judicious and widely adopted arrangement of 1856. 

 Meristeflla, Hall. Spiriferidw. ISoO. 



12th Regent's Eep. (Oct. 1859), p. 78, note. No diagnosis; sole ex. 

 cited, Atrypa naviformis, Hall, Pal. N. York, i, pi. xsiv, f. 1 a-c. lb. ii, 

 p. 76. (Sil.) Comp. Mtrietina, Hall. 



