MYALINA. 



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water genus) be retained the name " Mytilus " for his Permian species 

 Monogr., 1850, p. 159). With this view he fell into error, as de Koninck's shells 

 were of undoubtedly marine habitat; and, though somewhat akin to the Coal- 

 measure Mytiliforni shells, perfectly distinguished by the non-terminal umbones, 

 trifid anterior muscle-scars, absence of rostral septa, and the anterior lobe 

 characteristic of the latter shells. 



The name " Myalina " was adopted by Bronn and by Morris (2nd edit.) in 

 their respective catalogues. Geinitz referred the Permian species to Geroillia, 

 a genus with which there is little or no anatomical connection ; for that genus 

 possesses a well-marked anterior lobe and several pits along the hinge-line for the 

 cartilage. It was M'Coy who first adopted the generic name Myalina in a descrip- 

 tive work in 1855 (op. supra cit.), — but only for the Permian species, no mention 

 being made of the Carboniferous forms. 



In America the palaeontologists of the different State Surveys at once recog- 

 nised the genus as occurring in Carboniferous deposits, and a large number of 

 species were soon described. Bigsby gives the following list in his ' Thesaurus 

 Devonico-Carboniferus,' p. 308 : 



Myalina ancjulata, Meek and Worthen. 



— ■ aviculoides, Winchell. 



— concentrica, M. and W. 

 — • imbricaria, Winchell. 

 — - Kansasensis, Shumard. 



— Iowensis, Winchell. 



— meliniformis, M. and W. 



— Michiganensis, Winchell. 



— perattenuata, Meek and Hayden. 



Myalina pernseformis, Cox. 



— pterineceformis, Winchell. 



— rara, Winchell. 



— recta, Hawn. 



— recurvirostris, M. and W. 



— Sancti-Ludovici, W. and N. 



— squamosa, Hayden. 



— subquadrata, Shumard. 



— Swallovi, McChesuey. 



S. A. Miller enumerates twenty-eight species from North American strata in 

 his 'North American Geology and Palaeontology,' pp. 492, 493. Some of these 

 are probably synonyms, and one or two may be found to belong to Naiadites, but 

 a number of the figures referred to are characteristic of the genus Myalina. 



Baily in 1860 gave the name Myalina Foynesiana to a little Modioliform shell 

 from the Coal-measures of Foynes Island, co. Limerick, which was associated 

 with a marine fauna. The shell has neither the striated hinge, terminal beaks, nor 

 rostral plates of Myalina; and I have referred it to Modiola megaloba (PI. II, fig. 10). 



The Naiadites of the Coal-measures were in 1861 referred, by Mr. Salter, to 

 Myalina, but within one year he instituted the genus Anthracoptera for them, 

 being unaware that Dawson had described one form under the name Naiadites. 

 Mr. R. Etheridge, jun., adopted the name Myalina for the shell described by 

 Fleming as Mytilus crassus, at the same time showing that this shell did not 

 possess the terminal beaks and rostral septa of de Koninck's genus. Later on he 



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