FISHES OF THE DEVONIAN AGE. 4] 
western New York and southern Canada than in the more open waters of 
the area now oecupied by Ohio. In the exposures of the Corniferous lime- 
stone on Kelley’s Island, Lake Erie, at Sandusky, Delaware, and Columbus, 
Ohio, fragments or complete spines of Macheracanthus major and M. peracu- 
tus are not at all uncommon, but though collecting extensively myself in 
those localities I never obtained there a specimen of M. sulcatus. 
As will be seen by the section which accompanies the figure now pub- 
lished, the spines of this species were much narrower and more stiletto-like 
than the others, which rather suggest bayonets, and afford an interesting 
illustration of the device that gives strength with economy of material, 
viz, a prominent carina along the middle, with concave slopes to the acute 
edges. 
A fairly good figure of this spine was given, without a name, by Prof. 
James Hall, in the Geology of New York, part 4, page 174, and a reduced 
copy of Professor Hall’s figure is published in Dana’s Manual of Geology. 
The spines of WM. sulcatus are frequently, perhaps generally, twisted, as 
the pectoral spines of Gyracanthus formosus are. 
Formation and locality: Corniferous limestone; Milford, Ohio, and many 
places in New York and Canada. 
Order GANOIDEI. 
Suborder CHONDROSTEID&. 
Genus MACROPETALICHTHYS, N. & O. 
I have elsewhere’ defined this genus, and have reviewed its characters 
and relations to other fishes, living and fossil, at such length that it will not 
be necessary to go over the subject again in detail. The generic descrip- 
tion given by Drs. Norwood and Owen was very defective from the imper- 
fections of the specimen which served as a type. The essential generic 
characters may be briefly given as follows: 
Ganoid fishes of large size; cranium composed of large polygonal plates united 
by double sutures, which are nearly concealed. by the tubercled enameled surface; tu- 
berculation stellate, surface ornamented by double rows of pores and single-thread 
| Paleontology of Ohio, vol. 1, p. 290, 
