288 PALEOZOIC PALEONTOLOGY. 
SPIRIFER MACROPLEURUS (Con.). 
Plate: Xexaxes) Big.) le 
See, also, p. 318, pl. XX XVII. 
A single specimen referable to this species, belonging typically in 
the fauna of the New Scotland beds, has been observed in the Coey- 
mans limestone associated with Gypidula galeatus and other typical 
members of the fauna. It is a pedicle valve, and is smaller than the 
usual size of the species in the higher fauna, it having a length of 19 
mm. and a width of 28 mm. 
SPIRIFER ocTocosTAtTus Hall. 
Plate XXX., Figs. 5-8. 
1859. Spwrifer octocostatus Hall, Pal. N. Y., vol. III., p. 205, ply 28, 
figs. 4 a-e. 
Description.—Shell wider than long, the hinge-line shorter than the 
greatest width, cardinal extremities rounded, anterior margin broadly 
rounded. Pedicle valve rather strongly convex, most elevated on the 
umbo, beak prominent, incurved over the short, ill-defined concave 
cardinal area, delthyrium broadly triangular, the median sinus smooth, 
continuing to the beak, subangular in the bottom. Brachial valve a 
little less convex than the pedicle, most prominent in the middle, the 
mesial fold slightly or not at all elevated above the lateral slopes. 
Surface of each valve marked by about four prominent, subangular 
plications on each side of the fold and sinus. 
The dimensions of a nearly-perfect brachial valve are: length, 10 
mm.; width, 19 mm. 
Remarks.—This species has only been observed in the higher beds 
of the Coeymans limestone near Hainesville. All the specimens ob- 
served are fragmentary, and the finer surface characters have been 
destroyed by exfoliation, but near the front margin of one of the best- 
preserved specimens several conspicuous, concentric lines of growth 
may be detected. 
