DEVONIAN FAUNAS. 369 
ATRYPA RETICULARIS (Linn.). 
Plate LI., Figs. 1-4. 
See, also, pp. 236 and 286. 
The specimens of this species which occur in the Onondaga lime- 
stone are not essentially different from its earlier representatives. 
SPIRIFER sp. undet. 
A few fragments of a small, rather coarsely-ribbed species of 
Spirtfer, with strong, lamellose lines of growth, have been detected 
in the Onondaga limestone. The specimens have somewhat the aspect 
of Spirifer varicosus Hall, but in no case are they sufficiently well 
preserved to be identified with certainty. 
RETICULARIA FIMBRIATA (Con.). 
Plate LI., Figs. 8-11. 
1867. Spirifera fimbriata Hall, Pal. N. Y., vol. IV., p. 214, pl. 33, 
; figs. 1-21. 
Description.—Shell transversely subelliptical in outline; hinge- 
line shorter than the greatest width; cardinal extremities rounded. 
Pedicle valve strongly convex on the umbo, the surface sloping in a 
regular curve to the lateral and front margins, but curving much 
more abruptly to the cardinal margins; depressed along the median 
line in a more or less sharply-defined, shallow, rounded sinus; beak 
small, incurved over the area; cardinal area rather high, concave, 
not sharply defined. Brachial valve a little less convex than the pedicle, 
often somewhat flattened toward the cardinal extremities; mesial 
fold rather abruptly elevated in front, but scarcely defined at the beak. 
Surface of each valve marked by from five to eight low, rounded, 
obscure plications on each side of the fold and sinus, and by more 
or less imbricating, concentric lamelle of variable width, each one of 
which is marked by a row of small, radially elongate nodes having 
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