COPE ON ICHTHYIC FAUNA OF THE GREEN RIVER SHALES. 809 
prominent. In section II, the scuta are not wider than long, and have 
but one, a median tooth, which is the extremity of a median longitud- 
inal carina. The species of section I are D. dentatus, D. analis,and D. 
pectorosus ; those of section II are D. humilis and D. altus. 
Char. specif.—Fin-radii: D. I—13; A. I. 35. Vertebre: dorsal, 18; 
caudal, 21. The greatest depth enters the length without the caudal 
fin two and a half times, and the head enters the same nearly three and 
one-third times, The eye is large, its horizontal diameter a little exceed- 
ing the length from its border to the inferior edge of the premaxillary 
bone, and a little greater than one-fourth the length of the head. The 
premaxillary and dentary bones are short and deep, the latter with a 
deep notch on the anterior border; both are directed upward. The 
maxillary bone is long and narrow, and curved backward at its lower 
end, which reaches a point below the anterior border of the orbit. The 
profile behind the premaxillary bone is nearly horizontal; above the 
posterior part of the orbit, it rises, and a compressed supraoccipital 
crest carries it to the gently convex dorsal line. The abdomen is con- 
vex, and is about as long as the caudal region. The last dorsal ray rises 
above a point anterior to the first anal ray. The caudal is deeply 
forked. The ventrals originate at a point barely in advance of a verti- 
cal line from the first dorsal ray. The pectoral fins are short. The 
scuta of the inferior median line are large and acute. The scales are 
rather small, and are delicately grooved; twenty rows may be counted 
between the vertebral column and the dorsal fin. 
Measurements. 
M. 
POtAR TEMP tiie serehce uss Sidcie dcsice Sie cicadas pra eyeiaye cme aie: elaine er eice ae hose be 0.365 
Length of head ...-.. --.--. .-e 200 conn ne ween ne cee cee eee cence renee neenee eens 0.083 
Length (axial) to below first dorsal ray.--. 2-2 2220 cee cece ee cee eee ee cece eens 0.145 
Length to above first anal ray... .-- 20. 2-2. een ee cee cee cence cee eee eee cee 0,185 
Length to base of external caudal rays......---.- +22 ee eee cece cece cee eee eee 0.285 
Depth at orbit... woe ee eee ee cee ee eee teens eee eens cece ee ee UL055 
Depth at naeiaee, obi eint cis ayeja ta Stee sinpere oh Sle tcime ale Shale Melsleten somase gue anaeveeteist 0,098 
Depth at first dorsal i ial icatese iSeries aarcoNceeaesaeee sees ce: OLLLS 
Depth at; middlecanal fay vscccaowsssecacccaecccecaseeceaeesine easiess ds cece acee 0050 
Depth at base of caudal fin. ..... 2.0.52 ee ee eee eee eee f siepa vel sostervtetonaie:giavai 0.030 
This species is represented by a single specimen of the size of a small 
Shad and exceeding the Herring. It is in fine preservation. 
DIPLOMYSTUS ANALIS, Cope, sp. nov. 
Radial formula: D.I. 11; A.I. 40. Vertebre: dorsal, 17-18; caudal, 
23-24, This species is mare elongate in proportion to its depth than 
either of the other species, the length being three times the greatest 
depth. The anal portion of the body is considerably longer than the 
abdomen, and the anal fin is long and with short rays. The ventral fin 
commences well in front of the dorsal, whose last ray is considerably in 
advance of the first anal ray. The pectoral fin reaches the ventral, and ” 
