468 Gencral Notes. [May 
GENERAL NOTES. 
GEOLOGY AND PALZONTOLOGY. 
American Triassic Rhynchocephalia.—The reptilian genus 
Typothorax was described by the writer in 1875 in the Hook of 
Captain G. M. Wheeler to the Chief of Engineers, U. S. A., from 
eculiar osseous dermal plates, which he found in the Taai 
a lands of New Mexico. Additional material recently ex- 
amined furnishes a-good deal of information as to the characters 
of this form, and indicates that its position is somewhere near to 
the genus Aétosaurus of Fraas, in the order Rhynchocephalia. 
This is an important addition to American palzontology, since 
undoubted members of this order have not been hitherto found 
on this continent, excepting perhaps the Champsosauride. 
pieces, which belong undoubtedly to the type species, 
Satay pha coccinarum Cope, include two ribs with corresponding 
ermal scuta, two femora, and some loose dermal scuta. There 
are tabiy other parts of the animal preserved. The ribs are 
remarkable for their wide expansion, so that their edges meet, 
forming a continuum; but they are not joined suturally. Each 
rib is overlaid by a band-like dermal scutum of similar length 
and width. The inferior face of one edge of the dermal scu- 
tum is bevelled so as to make a ga ping groove, while the 
plate and rib are obtuse and appressed at the opposite edge. 
T he 
adjacent pair of bones, thus forming an uninterrupted cuirass, 
as in the armadillo. The femur is curved, with a third trochanter 
and a bilobate external condyle. No distinct great trochanter. 
The dermal armature resembles that of Aëtosaurus, but differs 
of them in either genus. The surface of the scuta is sculptured 
20 shallow pits in Zypothorax coccinarum. The species is as 
as the Mississippi alligator. 
This, genus offers an interesting parallel in. the structure of its 
bryonic stages in that order. There ean be little doubt but that 
more complete korre of this genus and its allies will throw 
light on the origin of the order of Testudinata. 
It is important to observe that, like the Aétosaurus in Wiirtem- 
berg, the Typothorax accompanies the genus Belodon in the beds 
near the summit of the Trias.—£. D. Cope. - 
