1878.] 693 {[Cope. 
conspicuous cutting edge, as in Myletes. Two conical teeth behind the man - 
dibular series. The belly is armed with spiniferous ? interhemal bones. 
This form is related to Myletes precisely as Stethaprion is to Tetragonop- 
terus. But one species is known to me, 
Char. Specif. Form orbicular, the dorsal region very convex ; the ab- 
dominal outline still more so. The depth is eleven-twelfths of the length less 
the caudal fin, and the length of the head enters the latter three and two- 
tenth times. The depth of the head from the superior border of the post- 
temporal bone equals the length. The eye is large, entering the length of 
the head three and one-sixth times, and the convex interorbital space one 
and one-half times. The chin projects a little beyond the premaxillary 
border, and the end of the toothless maxillary bone is immediately below 
the proximal extremity and below the nostrils. 
Radii; D. I. 17; A. 39; V. 7; P. 14. The ventral fins are very small, 
and their base is contracted, so that the spines are arranged nearly in a 
circle, the inner and outer being of equal length. The pectorals are small, 
marking only the third of the distance to the line of the ventrals. The base 
of the anal makes an angle of only 25° with the vertical ; its anterior rays are 
little prolonged. The base of the dorsal is oblique downwards and back- 
wards, and the first ray marks a point at .4, the distance between the bases 
of the pectoral and ventral fins. The length of the base of the adipose dorsal 
is two thirds that of the rayed dorsal. Ventral spines 25, the anterior re- 
curved and simple, the posterior more or less bifurcate. The head of the 
predorsal spine is anvil-shaped. The suborbital bones are narrow ; the an- 
terior is the widest, and is triangular with the long apex superior. 
Scales between the lateral line and the ventral fins, 39-40, those of the 
lateral line (in front) larger than the others. Total length, M. .075; of 
head, .020 ; to line of ventral fin, .033; of anal, .046; of caudal fin, 060. 
First dorsal ray equidistant between base of caudal marginal ray and end 
of muzzle, measured in straight lines. Color golden, excepting the su- 
perior half of the region above the lateral line, which is dove-color in 
spirits. No spots of any kind. 
Coll. of 1877. 
956. MYLETES HERNIARIUS Cope, Proceed. Acad. Phila. 1872, p. 268. 
Coll. of 1873. 
The specimen here recorded differs slightly from the type in some de- 
tails. Dorsal radii in both, 17; anal in type, 32; in new specimen, 35 ; 
spines in type 46; in new specimen 51. There is a faint eye-like spot on 
the side in the new specimen, not seen in the type, and some indistinct ver- 
tical shades. 
Coll. of 1873. 
97. MYLETES NIGRIPINNIS, sp. Nov. 
Premaxillary teeth in two series, which are in close contict. The an- 
terior series is curved, and consists of ten teeth with a space as wide as a 
tooth in the centre ; the posterior series is uninterrupted, and consists of 
