﻿ACTINOPTERIA. 



59 



Avicula Ibergensis, F. A. Romer, 1 and Pt. flabella, Conrad, 2 differ from it in 

 most of the same particulars as does Pt. fasciculata, Goldfuss. 



Pt. Sechendurfii, F. A. Romer, 3 appears to have fewer costse, a blunter umbo, 

 and a straighter anterior side. 



Avicula Isevicostata, Follmann,' 1 seems to be a decidedly more transverse shell, 

 with a larger and more prominent umbo, blunter ridges, and no minor ribs. 



Pt. Paillette! , de Verneuil, 5 is distinguished by its greater obliquity and its 

 large and smooth hind wing. 



Pt. subfasciculata, de Verneuil 6 (which is separated from Pt. fascieulata, 

 Goldfuss, by its smaller size, smaller posterior ear, and the absence of minor 

 ribs), seems to differ from the present shell in having flat interspaces and no 

 alternations in the ribs. 



4. Genus. — Actinopteria, Hall, 1883. 



Hall describes this genus or sub-genus as " characterised from Pterinea in the 

 absence of a broad striated ligamental area, and strong cardinal and lateral teeth. 

 Right valve sub-convex. Surface with fine rays." Freeh, on the other hand, 

 regards it as merely a group in the genus Avicula, and intimates that living forms 

 which are classed with Avicula. fall within its limits. To this latter genus it 

 is certainly more closely allied than to Pterinea,, but it appears to be very 

 different in general aspect from its typical forms, and I should be inclined 

 to regard Barrois as right in accepting it as a genus or sub-genus. It is charac- 

 teristic of Devonian Beds, and many forms occur in Europe and America. It is 

 especially well represented in the localities now under review. 



1 1855, F. A. Bonier, ' Beitr.,' pt. 3, p. 35, pi. vii, fig. 3. 



2 1884, Hall, ' Pal. N. T.,' vol. v, pt. 1, p. 93, pi. xiv, figs. 1—21 ; pi. xv, figs. S— 10 ; and 

 pi. lxxxiii, figs. 11, 12. 



3 1843, F. A. Eonier, ' Verst. Harzgeb.,' p. 23, pi. xii, fig. 28. 



4 1885, Follmann, ' Verh. Nat. Hist. Vereins Preuss. Rheinl.,' vol. xlii, p. 195, pi. v, figs. 4, 4 a. 



5 1855, de Verneuil, 'Bull. Soc. Greol. Fr.,' ser. 2, vol. xii b, p. 1003, pi. xxix, fig. 3; and 1891, 

 Freeh, ' Abhandl. Geol. Specialk. Preuss.,' Band ix, pt. 3, p. 83, pi. 9, fig. 3. 



G 1869, de Verneuil, ' Faun. Devon. Bosphore,' p. 32, pi. xx, fig. 6. 



