998 The American Naturalist. [ November, 
GEOLOGY AND PALEONTOLOGY. 
A Batrachian Armadillo.—The significance of certain fragments 
which I observed several years ago in Permian material from Texas, 
has been established by a more complete specimen which I have re- 
ceived from the same locality. This consists of a portion of the skele- 
ton, which includes ten consecutive vertebrae and their appendages, of 
the rhachitomous type, similar in general to those of Trimerorhachis. 
The genus differs from Trimerorhachis in this important respect. The 
neural spines are elevated, and the apex of each sends a stransverse 
branch which extends in an arch on each side tothe ribs. These spin- 
uous branches touch each other, forming a carapace. Above and cor- 
responding to each of them is a similar dermal osseous element, which 
extends from side to side without interruption on the median line, 
forming a dermal layer of transverse bands which correspond to the 
skeletal carapace beneath it. To this remarkable genus I propose to 
give the name of Dissorophus. It is a veritable batrachian armadillo. 
As to species characters, it is to be remarked that the intercentra are 
longer in proportion to their width thanin the Trimerorhachis insignis. 
The heads of the ribs have a small free truncate angle below their cap- 
itulum. The extremities of the spinous roof-processes are free from 
each other for a short distance, and each has a depressed rounded sharp 
edge. The dermal bands above them terminate a little proximad of 
them and in a similar manner, and their extremities are closely ap- 
pressed to the surface of the band below them, with which they slightly 
alternate. Their surface is very coarsely rugous, with ridges and fossae, 
whose long axes agree with those of the segments. This species I pro- 
pose to call Dissorophus multicinctus. Length of ten vertebrae in 
place 93 mm. ; width of intercentrum 16; length of do 9; elevation to 
roof 30; thickness of carapace 8; width of a carapacial band 9 ; length 
of do on curve 75. The species appeared to have been about the size 
of the Japanese salamander Megalobatrachus maximus. 
The genus Dissorophus adds another to the remarkable forms already 
known from the American Permian. It is remotely approached by the 
genus Zatachys Cope, where a dermosseous scute is codssified with the 
apex of the neural spine.—E. D. Copr. 
Cope on the Temporal Part of the Skull, and on the 
Systematic position of the Mosasauride—A reply.—In the 
September Number of this Journal Prof. Cope has published a review 
