i 
1872.] 479 [Cope. 
icious rock cap the foot-hills of the range, forming their southern slopes 
with the southern dip, appearing to be nearly conformable to the shales. 
Their escarpments are to the northward, and the outcrops are fissured 
in every direction, the debris being scattered over the lower levels. On 
one of these rather elevated valleys I found abundant remains of the 
trunks of ancient forest trees, completely silicified. Many of the trunks 
must have measured five feet in diameter, and display the concentric 
laminz of the dicotyledonous type. They were variously altered ; some 
becoming chalcedony, and others opal; portions being black, red, yellow, 
purple, or white, of great purity. 
At another outcrop of the silicious strata, a few miles distant from the 
above locality, the rock was found to be variegated by concentric bands 
of red, yellow, black, and white. Though fine in texture, it is not suf- 
ficiently translucent to constitute a valuable agate, which it otherwise 
resembles. 
The connection between these silicious strata and the silicified wood 
seems apparent. The silica deposited in sufficient quantities to form 
strata of from twenty to forty feet in thickness, would suffice to impreg- 
nate submerged forests. That these strata are of sedimentary age is not 
settled, but they seem to be conformable to, and later than the tertiary 
shales just described. 
TRICHOPHANES. Cope. Gen. nov. 
Allied to Erismatopterus, Cope, and to the family of Cyprinodontide. 
Dorsal and anal fins short, each with a long and short spinous ray on the 
anterior margin. Ventrals beneath the dorsal. Operculum, with a 
longitudinal keel above. Mouth with wide gape, extending beyond orbit. 
Scales wanting, represented by rigid fringes or hair-like bodies. 
Several important characters of this genus are not very distinctly dis- 
played by the specimen described. This is especially the case with the 
maxillary region. The premaxillary bone evidently forms a large part 
of the arcade of the mouth, but whether the whole, is not certain. The 
presence of teeth, and number of branchiostegal radii, cannot be stated. 
Other points, more definitely exhibited, are a preoperculum without 
serrations, directed a little obliquely backwards ; a coracoid of little 
width; an inferior postclavicle with a superior (proximal) conchoidal ex- 
pansion and long, slender shaft, extending to the anterior extremity of 
the femora. The latter are quite slender and acuminate anteriorly, and 
grooved to the apex, but apparently not furcate. They do not present 
any marked posterior union. Vertebree not elongate. 
Caudal fin furcate. Interneural spines wanting in front of dorsal fin ; 
those of the anterior rays very strong. Interhemals of the anterior anal 
rays similarly strong. Caudal fin embracing one vertebra, and sup- 
ported by separated hamal spines. 
The characters which separate Trichophanes from Hrismatopterus, are 
seen in the large mouth and short muzzle, and in the peculiar covering of 
the body. Inthe former character it resembles some of the Scopelt, 
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