336 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.45. 



Actinopteria reticulata Weller from the Decker limestone of New 

 Jersey is also a closely related form.^ 



Formation and locality. — Edmunds formation, Field Point, on west 

 side Cobscook River, Edmunds Township, Washington County, Maine 

 (loc. No. 8.1.8D). 



Holotype.—C&t. No. 58956, U.S.N.M. 



COMMENTS ON AVICULA ? RETICULATA SOWERBY. 



J. de C. Sowerby described a shell from the Aymestry formation 

 under the name Avicula ? reticulata, of which closely related, if not 

 identical representatives, are found in the rocks of the Eastport 

 quadrangle. 



The original description is as follows: 



Avicula ? reticulata Sowerby. 



1839, Sil. syst., p. 614, pi. vi, fig. 3. 



(Hisinger Petr. Suec. 57, t. xvii, f. 13?) 



Ovate, broad, pointed toward the beaks, rather convex, ribbed; ribs numerous, 

 decimated by the lines of growth; one valve nearly flat; ears unequal, one very large, 

 right angled . 



Length 2 inches, width 1 inch 8 lines. 



Loc, Croft Valley, Aymestry. 



Sowerby in the text records the species from the Aymestry lime- 

 stone, but on page 618 it is also listed among the fossils of the lower 

 Ludlow, loc. Myddleton Hall, Caermarthenshire, and on p. 628 from 

 the Wenlock limestone, loc. Falfield-Tortworth. 



1855, M'Coy, Brit. Pal. Foss., p. 263, redescribes the species and 

 gives it the name Pterinea sowerhii. Ref . and syn. — Avicula reticu- 

 lata (Sow.) Sil. syst., t. 6, fig. 3 (not of Hisinger nor Goldfuss). His 

 description follows: 



Sp. ch., obliquely ovate, depressed, slightly convex, greatest length along the pos- 

 terior slope, which is straight and defined; posterior wing gently arched, scarcely 

 extending beyond the shell; its posterior edge slightly and uniformly concave; sur- 

 face radiated by slightly irregular obtuse ridges, about their thickness apart (five in 

 two lines about the middle, at one inch from the beak), partially interrupted by thin 

 concentric imbrications from one to two lines wide, having the radiating ridges obsolete, 

 or nearly so, on their rostral half; radiating ridges of the wing rather larger, strongly 

 marked only about the middle. Length from beak to respiratory angle two inches 

 six lines; length of posterior wing 62/100, width of ditto 44/100; width from middle of 

 hinge-line to ventral margin 97/100, depth of one valve 10/100. 



This fine species differs from the Pterinea reticulata of the original Continental 

 authors in its more elongate form, smaller posterior wing, with its gently concave 

 posterior edge, and the comparatively few, broad, thin imbrications interrupting the 

 radiating ridges. 



Position and locality, Aymestry limestone, Leintwardine, Shropshire. 



Freeh ^ makes Avicula reticulata Goldfuss the type of his "Gruppe 

 der Avicula reticulata Goldfuss sp.," and distinguishes this species 



1 Pal. Fauna, Geol. Sur., New Jersey, vol. 3, 1903, p. 245, pi. 22, fig. 3. 



2 Freeh Dev. Aviculiden Deutschl., 1891, p. 34. 



