184 REPORT—1874. 
by the maxillary bone, for an extent of 43 inches beyond the premaxillaries; and 
this border shows still more distinct traces of alveoli, of a circular form, about a 
line in diameter, and rather closely set in a single series, The fore part of the orbit 
is very unequivocally displayed, the smooth under or inner surface of the bone 
forming that part being entire; and this shows the fore part of the orbit to be 
formed, partly by the maxillary, partly by a lachrymal or prefrontal bone in close 
sutural union therewith ,—a structure which does not exist, to my knowledge, in any 
recent or fossil fish with a dentigerous superior maxillary bone. Where the sub- 
stance of the bone has been detached so far as to expose the exterior layer in con- 
tact with the coal, as, e.g., on the frontal and part of the prefrontal bones, the ex- 
terior surface of those bones is shown to have been impressed by subhemispheric 
or elliptical pits, from 1 line to 13 line in diameter, and with intervals of half that 
extent: and this coarsely pitted character agrees with that Pe by the outer 
surface of the similarly broad and flat crania of the Labyrinthodont Batrachia, e. g. 
Trematosaurus, Cupitosaurus, and Labyrinthodon proper.....The traces of the 
nostrils are less definite and satisfactory than the remains of the orbits; but the 
latter appear to me to be decisive against the piscine nature of the fossil.” —Owen. 
The teeth are conical and slightly curved, grooved below, and smooth towards 
the tip. The peripheral dentine gives off simple, slightly undulating processes 
towards the centre. Pulp-cavity rather large. If, as is probable, the section here 
described was made in the upper part of the tooth, the structure has not a little 
resemblance to that of Labyrinthodon leptognathus. 
B. PLANICEPS, Owen. 
Locality. Pictou Coal-field, Nova Scotia. 
References. Owen, Q. J. Geol. Soc. vol. x. p. 207, t. ix. [1853].—Jd. Palzonto- 
logy, p. 184 [1860].+ Dawson, Acadian Geology, 2nd ed. pp. 328, 360, figs. 
137, 141 [1867]. 
Brachydectes, Cope. 
“This genus is indicated by two rami of a mandible and a portion of a premax- 
illary only..... The teeth are elongate cylindric cones, with their acute tips turned 
a little posteriorly. The fractured ones display a large pulp-cavity. he three 
premaxillaries preserved are similar, but without curvature of the tips. They do 
not exhibit striz or any other sculpture. So far as the remains go, the genus is 
nearer Hylerpeton than any other.” 
B. NEWBERRYI, Cope. 
Locality. Coal-measures, Linton, Columbiana County, Ohio. 
References. Cope, Proc, Acad. Nat. Sci. Philadelphia, 1868, p. 214.—Jd. Synopsis, 
p. 14.—Id. Supplement, p. 8. 
Chalcosaurus, Von Meyer. 
The skull only is known. Von Meyer's description (from a photograph) is aps 
pended. The few characters furnished seem to associate Chalcosaurus with the 
Brachyopina. 
“The skull is of nearly equal length and breadth, which amount to 150 millims., 
not quite half a Paris foot. The hinder tg appears to be injured ; the obtusely para- 
bolic anterior end is well preserved. The regularly oval orbits are situated in the 
middle of the anterior half of the skull. They appear to measure 29 millims. in 
length and 20 millims. in breadth, and are hardly more than their own length 
distant from each other. The margin of the [lower] jaw is set with a single row 
of small teeth. Indications of sutures are present, which do not, however, suffice 
to determine the composition of the skull.” 
C. rosstcus, Von Meyer. 
‘ Locality. Kupfer-Sandstein of the southern side of the Obschtij-Syrt, near Oren- 
urg. 
References. Von Meyer, Paleontographica, vol. xv. p. 124, t. xxi. fig. 1 [1866]. 
