156 NEW YORK STATE MUSEUM 



Actinopteria textilis (Hall) 



Plate 19, figures 1-3 



Avicula textilis Hall. Palaeontology of New York. 1859. 3:288, pi. 52, 



fig- 9, 10 ; Pl- 53, fig 2, 3, 5, 7, 10 ' 



Pterin ea textilis? Billings. Palaeozoic Fossils. 1874. v. 2, pt i, pi. 4, fig. i 



Mr Billings hesitatingly referred to this species a specimen of which he 

 gave a figure but to which no reference was made in his text. Its associ- 

 ation on the plate with Gaspe fossils and the actual occurrence of the 

 species therewith leads to the inference that his specimen was from these 

 limestones. The shell is very abundant here and not to be distinguished 

 from the New York forms occurring in the New Scotland (Helderbergian) 

 fauna, except that by virtue of different preservation the former show more 

 distinctly the character of the surface ornament which consist of primary 

 ribs separated by broad interspaces usually divided by a single intermediate 

 rib of small size. This simple ornament prevails over the adult body, but 

 the intercalary spaces become broken up toward the margin in old shells, 

 showing thereby a tendency to the finer alternating surface of A. c o m- 

 munis Hall, a common Oriskany species at Becraft mountain. 



Localities. About Grande Greve and elsewhere on the Forillon. 



Pterinopecten proteus Clarke mutation 



Plate 19, figures 2, 3 



See Pterinopecten proteus Clarke. N. Y. State Mus. Mem. 3. 1900. p. 32, 



pi. 4, fig. 4-8 



The group of shells represented by the Oriskany species Actinop- 

 teria (Avicula) textilis and var, are n aria Hall, Pterino- 

 pecten (A vicula) recticosta Hall and Pt. proteus Clarke, find 

 allied expression in the fauna of the Gaspe limestones in at least three 

 species. In all these there are but slight variations from the general type 

 of surface ornament though this may be greatly diversified within the limits 

 of a single species; yet it is all of the type of alternating and fasciculate ribs 

 crossed by fine concentric and elevated lines. There is also gradual passage 

 among them from the oblique form we would ascribe to Actinopteria, to the 

 more typical expression of Aviculopecten and thence to the erect form of 

 Pterinopecten. Without attempting, in face of present evidence, to analyze 

 the value of these divisions, we find that with such easy variations amongst 

 these species it is not well to insist on specific identities in all cases of the 

 Canadian with the New York shells. 



In describing Pt. proteus we noted the variability of the exterior in 

 shells of one type of outline. In the Gaspe limestones we find shells 

 approximating this outline but even more erect, and with the posterior wing 



