lliNi) — Noteii on the Homotaxial Equivalents, ^"c. 107 



Modiola megaloba, M'Coy = Myalina foynesiana, Eaily. PL v., 



fig. 6. 



In my monograpli on British Carboniferous Lamellibranchiata, 

 p. 62, vol. i., I pointed out that Eaily has erred in referring his shell 

 to 3fyalina, the absence of the striated hinge-plate at once separating 

 it from that genus and also from Xaiadites. Eaily's specimen from 

 Foynes is a cast of both valves, showing adductor muscle scars, and 

 the simple linear hinge-plate. Myalina, however, does occur in the 

 Foynes nodules. 



Locality — Foynes Island, = Horizon of Pendleside series. 



Myalina peralata, de Koninck. Fl. v., fig. 7. 



Myalina has terminal umbones and a striated hinge-plate. M. 

 peralata lias been known to occur in the Pendleside series in England. 



Localities — Foynes Island and Lisdoonvarna, = Horizon of Pendle- 

 side series. 



Posidoniella laevis, Brown sp. PI. v., fig. 8. 



This most common and characteristic species occurs practically 

 everywhere in England and Ireland in the shales which succeed the 

 Carboniferous Limestone. This genus is easily distinguished from 

 Posidoyiomya, with species of which genus Baily seems to have con- 

 founded it. Posidoniella has terminal umbones, and no anterior ear 

 or lobe, and is obliquely pyriform in shape. This shell has a vertical 

 •distribution from the Pendleside series to the Lower Coal Measures. 



Localities — Kilkee, = Horizon of Millstone Grit. Coor spa well, 

 Ennis ; Lisdoonvaina ; Foynes Island, = Horizon of Pendleside series. 



Posidoniella minor, Brown sp. PI. v., fig. 9. 



This shell is more quadrate and transverse than P. Icevis. It 

 appears to have the same vertical distribution. 



Localities — Foynes Island; Coor spa well, Ennis; Lisdoonvarna, 

 = Horizon of Pendleside series. 



Parallelodon semicostatus, M'Coy sp. PI. v., fig. 10. 



The type of this series was obtained at Manorhamilton. It is not 

 an uncommon species in the Yoredale phase of the Carboniferous Lime- 

 stone series in England and Scotland, and also occurs in the Pendleside 



