1020 General Notes. [December, 
a small median posterior marginal tubercle, which runs into a 
posterior cingulum, and is wanting from the L. penetrans. The 
tubercular has the three anterior cusps distinct as in Didymictis 
sp., while the heel is longer than in the known species of that ge- 
nus. Its external border rises into a prominent cusp with trian- 
gular base. The fourth premolar has a small heel on the inner 
posterior side, and an acute anterior basal cusp. The principal 
cusp is robust and the basal portion is widely. grooved posterior- 
ly (apex lost). True molars with an external cingulum. Enamel 
obsoletely wrinkled. Length of true molar series, .024; of fourth 
premolar, .0075; length of last molar, .008; width of heel of — 
second true molar, .005; length of crown of do., .007.—E. D. Cope. 
THE PERMIAN Formation oF New Mexico.—This formation is 
richly fossiliferous in New Mexico, and the vertebrates include 
several of the types already known from Texas and Illinois. 
Such are, among reptiles, the genera Diadectes, Dimetrodon and 
probably Clepsydrops. Of batrachians there are two genera, Ery- 
ops, and what is probably Zatrachys. Diplodus represents the 
fishes. All the individuals, and hence, probably, the species, are 
of smaller size than those of the Texan Permian, resembling in 
this respect those found in Illinois. Two species of batrachians 
of the genera above mentioned, are new, and may be described 
as follows: 
Eryops reticulatus— The most prominent peculiarity of this 
species is seen in the neural spines, which are not expanded at 
the summit as in 4. megacephalus, but have rather contracted 
apices. Another character is the sharply reticulate sculpture of 
the maxillary bones. The species is much smaller than the &. 
megacephalus, or even than the Trimerorhachis insignis, and the 
extent of ossification of the vertebral elements is intermediate be- 
tween the two species. The inferior surfaces of the intercentra 
are smooth, and the diapophyses are compressed. The occipital 
condyles are depressed and not very well distinguished inferiorly. 
The humeri have expanded extremities with enlarged epicondyles 
and well developed condyles, and no epitrochlear foramen. Width 
of occipital condyles, m. .016; elevation of dorsal vertebra, .024; 
width of intercentrum, .o11; length of intercentrum (below), 
.007 ; five maxillary teeth in .o15. 
Zatrachys apicalis—Represented by vertebrz and dermal bones, 
The summits of the neural spines are expanded, and the superior 
faces of the expansions are tubercular and have a median promi- 
nence. The expansions are sometimes large, resembling the 
dermal bones of crocodiles, and in that case the median proini- 
nence is a keel. On the smaller expansions the latter is a mere 
apex. There are narrow flat bones which I suppose to be neural 
spines, which are ornamented with inosculating ridges. A capit- 
ular head of a diapophysis is compressed. Intercentra well ossi- 
fied, those preserved without lateral notch. Inferior surface with 
