No. 431.] CARBONIFEROUS FISH REMAINS. 851 
basal portion, and tapers gradually toward the acuminate distal end ; its 
surface is ornamented with numerous longitudinal costae which increase by 
bifurcation, and by rows of small, rounded or spiniform tubercles occupying 
the intercostal spaces, these being especially numerous on the broad basal 
portion of the spine, and extending also over the proximal portion of the 
anterior branch. 
The above description is based upon the remarkable spine 
shown in Fig. 1, together with two or three imperfect specimens, 
all collected by Dr. Hambach from the St. Louis Limestone in 
the vicinity of St. Louis, Missouri. The large specimen has 
a total length of 21.5 cm., of which the anterior branch 
forms about four-sevenths and the posterior spine three- 
sevenths. It is nearly seven times the size of Æ. maccoyanus 

vitare are "p x both 
Fic. n AES Jermens p, ngr EM Toar Limestone; St. Louis, Mo. Late 
x i. fram 

+ 
hath aaa i 

ats ar than the natural sos. 
St. J. and W., which accompanies it in the same formation, and 
twice that of E. jonesi M'Coy, the largest known European 
species. From both of these the present species differs not 
only in size, but also in the form of cross section and denticula- 
tions of the anterior branch, as well as in the general surface 
ornamentation. It appears improbable that the anterior branch 
was terminated by a cluster of denticles, but there is a double 
row of about twenty robust conical enameled bosses along the 
flattened face of this arm, which have evidently become obtuse 
through wear. This flattened face was probably entirely exposed, 
but there is reason to believe that the opposite, or more convex 
face, was buried in the integument. Its smooth surface pre- 
sents the same appearance as the inserted portion of most fin 
spines, and betrays none of the usual indications of wear. 
