§30 ; General Notes. [ December, 
Reptilia, and as probably the ancestral group from which the lat- 
ter were derived. This approximation is seen in the scapular 
arch and humerus, which nearly resemble those of the Mono- 
tremata, especially Echidna; and in the pelvic arch, which Owen 
has shown in the Axomodontia to resemble that of the Mammals, 
and as Prof. Cope pointed out, especially that of Echidna. The 
tarsus is also more mammalian than in any other division of rep- 
tiles. In the genus Dimetrodon the coracoid is smaller than the 
epicoracoid, as in Monotremes. The pubis has the foramen for 
the internal femoral artery. 
The discovery of the Pe/ycosauria established the important 
fact that the first land Vertebrata possessed a chorda dorsalis. 
A species of Dimetrodon was described under the name of D. 
cruciger. It is characterized by the enormous length of the neu- 
ral spines of the lumbar vertebrae, which form the dorsal fin seen 
in other species of the genus. They are found in masses adhering 
together like sticks or branches of bushes. In this species the 
spine sends off, a short distance above the neural canal, a pair of 
opposite short branches, forming a cross. At various more ele- 
vated positions there are given off tuberosities which alternate 
with each other. They form on several consecutive spines 
oblique rows. The spines are broadly oval in section, the long 
axis antero-posterior, and have a shallow groove on both the 
anterior and posterior aspects. The centra are elongate as com- 
pared with their other diameters, and are much compressed 
between the articular extremities, leaving a strong inferior median 
obtuse rib. Articular faces of zygapophyses oblique. Diapophy- 
ses short and robust, with large costal faces, and standing below 
the prezygapophyses. 
MEASUREMENTS. M. 
METO POSTEO. ....cceccceccersecsecsresnsessres 043 
Diameter of centrum { vertical at end SiG owen te vee oy aS 
transverse at ebd. osios, ees ck Semen hele rAr .030 
Elevation of posterior zygapophyses above centrum........+-+- Seis ON <4! 1025 
F *¢ cruciform process s A A TN .058 
Expanse of posterior zygapophyses..........cccseeecseescccasstenenscts pars 
n * crucifo e E (eee bee aes a a wens -O4 
: F SMLELO-POStETION. oe occ ca cess s+ esse wee oes -030 
Diameter of spine at base vay post 020 
inaa e E a nes cere sen 
antero-postericr.... sss sses sesers eoes o 
7 «u „O9Ö above bas 
2 oS Sy tranaverse ao ey ne a .o16 
Length of several pieces of neural spines.......-c00.- eee e cree ee eeneeree -140 
Discovery oF Recent GLACIERS IN WyoMING.—It was not known 
until Guring the past season that genuine glaciers existed within 
the limits of the United States, east of the Pacific coast, but last 
summer as two of the divisions of the Geological Survey under my 
_ charge were exploring the Wind River mountains in Wyoming Ter- 
ritory, we found living glaciers on the east side of the range. On 
the east base of the Wind River peak, which is at the south end 
of the range, there is a mass of snow and ice, goo yards long an 
