530 On BracMopod Nomenclature. 



but I would restrict Terehratula to the species in actual 

 genetic connexion with T. terebratula = ? T. bisinuata. The 

 forerunners of such species would be non-plicate, perhaps 

 uniplicate, before becoming biplicate. Biplicate Terebratulids 

 are polygenctic descendants from many non-plicate forms : 

 sometime they must be separated from Terehixitula into their 

 special genetic series. 



For a series of Cretaceous biplicate Terebratulids, which 

 will no doubt prove to be separable enough from the Tertiary 

 series, the name Musculus, Quenstedt, seems to be available. 



Genus Musculus, Quenstedt, 1868. 



Type Terehratula acuta, Quenstedt. 



Ref. Petref. Deutschl. ii. pp. 4, 27, 384, pi. xlviii. fig. 7a 



For a Jurassic biplicate series, the T. maxillata group, 

 very separable from other Terebratulids^ the name Epithyrisy. 

 Phillips, is available*. 



My beijt thanks are due to Mr. B. B. Woodward, F.L.S., 

 and to Mr. C. Davies Sherborn, F.G.S., for invaluable 

 bibliographic assistance in connexion with the investigations 

 for this communication ; also to Mr. W. D. Lang, F.G.S., 

 for kind answers to various enquiries. 



Appended are a few of the synonyms by which Terehratula 

 terehratula has been known ; these names have been attached 

 to the figures of Colonna or Klein, or else to the description 

 by Linne. 



Terehratula terehratula (Linn^). 



1G16. Concha rarior anomia, &c., Colonna. 

 1753. Terebratuh rugosa, Klein f- 

 1758. Anomia terebratiila, Liun^. 

 1785. Terehratula terehratula ; Tbimberg. 



1787. Lamjms terehratula ; Meuschen, Mus. Geversianum, p. 438, 



1788. Terehratula pUcata, Retzius. 



* See above, p. 528. 



t Klein's statement is " Terehratula .... § 427 species 1. simplex; & 

 rwjosa, Fab. Columnae de Purp. Cap. xii. § 3, pag. 32 ... . Icon exstat 

 in Tab. Nostra xi. No. 74." Terehratula ruyosa seems therefore to desig- 

 nate the biplicate shell figured by Colonna, § 3, p. 32, and reproduced by 

 Klein ; Terehratula simplex may have been intended to designate the 

 non-plicate Terehratula figured by Colonna in p. 33, § 5. 



