PALEONTOLOGICAL BULLETIN, No. 32. 
Second Contribution to the History of the Vertebrata of the Permian Forma- 
tion of Texas. By EH. D. Cope.* 
_ (Read before the American Philosophical Society, May 7, 1880.) 
Since my synopsis of this subject, published in May, 1878, the accession 
of much new material had enabled me to make a number of important 
additions to it. Notes which record scme of these may be found in the 
American Naturalist for September and December, 1878, and for April — 
and May, 1880. The substance of these is included in the present essay. 
At the meeting of the National Academy of Sciences, held in New York, 
in November, 1878, I pointed out that the scapular arch in the Pelycosauriat 
consists of scapula, coracoid and epicoracoid, which form a continuum in 
the adult, in the same way as the three elements of the pelvis in the same 
group form an os innominatum. The tibiale and centrale of the tarsus 
unite to form an astragalus which has no movement on the tibia. The 
fibulare forms a calcaneum. The distal side of the astragalus presents 
two faces, one of which receives a large part of the proximal extremity of 
the cuboid. 
The structure of the scapular and pelvic arches is identical with that 
already described by Owen as belonging to the Anomodontia. Several im- 
portant characters distinguish this group from the Pelycosauria, but the 
two together form an order which I have thought must, for the present at 
least, be retained as distinct from the Rhynchocephalia. The characters 
of this order, with its two sub-orders, are as follows : 
THEROMORPHA Cope. Scapular arch consisting at least of scapula, 
coracoid and epicoracoid, which are closely united. Pelvi¢ arch consisting 
of the usual three elements, which are united throughout, closing the obtu- 
rator foramen and acetabulum. Limbs with the phalanges as in the am- 
bulatcry types. Quadrate bone proximally united by suture with the 
adjacent elements. No quadratojugal arch. 
Pelycosauria. Two or.three sacral vertebree ; centra notochordal ; inter- 
centra usually present. Dentition full. 
Anomodontia. Four or five sacral vetebree ; centra not netochordal ; no 
intercentra. Dentition very imperfect or wanting. 
The Rhynchocephalia have no distal ischio-pubic symphysis, and appar- 
ently no epicoracvid bone. They have an obturator foramen, and a quad- 
ratojugal arch, ° _ 
The order Theromorpha approximates the Mammu«tia more closely than 
any other division of Reptilia. This approximation is seen in the scapular 
arch and humerus, which nearly resemble those of the Monotremata, 
especially Echidna ; and in the pelvic arch, which Owen has shown in the 
sub-order Anomodontia to resemble that of the Mammals, and as I have 
* Abstract read before the National Academy of Sciences, April 20, 1880, 
+See Proceed. Aimer, Philos. Soc., 1878, p. d11 and 528, 
