524 CARPAL AND TARSAL BONES OF BIRDS. 
bearing, and Petite Anse lay right in the line of a series of Cretaceous 
te A reov ë 
of Calcasieu, between which ee the sulphur bed, are pobre repre- 
sented in the Cretaceous of northern Louisiana, while totally foreign to 
any of the Tertiary stages; erie although the great gypsum bed has not 
aey sen at oe Anse, it lies in the proper line of dip, and seems to . 
mplement to be looked for, of the great rocksalt bed. These 
‘iia mins hae of proof, it is true, but weigh heavily when we 
consider the simplicity of the geological structure of the Mississippi em- 
ayment; where departures from the general rule are so unlikely as to 
throw the burden of proof upon whosoever maintains their existence. 
On THE CARPAL AND ena, Bones or Birps.—By Pror. En- 
WARD S. Morse. 
Tue author stated that he had followed with great interest the 
work of Huxley, Cope, and others in tracing out the ornithic char- 
acters in the Dinosauria. While following these relations he had 
noticed a marked difference in the characters of the carpus and 
tarsus of the two classes. It seemed strange that a group of 
bones so persistent in the reptiles as well as in the mammalia 
should be so obscure or wanting in birds. Owen objects to the 
term tarso-metatarse as he believes the existence of a tarsus has 
not been demonstrated. W. S. Parker, in 1861, on the osteology 
of Baleeniceps, questions if the lower articular portion of the tibia 
is not the homologue of the mammalian astragalus and not an epi- 
physis. Gegenbaur has now shown that in one stage of the young 
bird there is a proximal tarsal ossicle, and a distal tarsal ossicle, 
the first one anchylosing with the tibia, the distal one likewise an- 
chylosing with the metatarse. Thus, the term tarso-metatarse is 
quite proper. While this was a great step toward a proper under- — 
standing of these parts, Mr. Morse believed that a nearer relation 
would be found in the discovery of another proximal tarsal bone. 
In those reptiles he had examined, whatever the number of tarsal 
- bones, there were always in the proximal series one corresponding 
to the tibia, and another corresponding to the fibula. He had 
found this feature in birds. In studying the embryos of the eave 
swallow, bank swallow, king bird, sand piper, black bird, cow 
black bird, blue bird, chirping sparrow, yellow warbler, and Wil- 
son’s thrush, he had found three distinct tarsal bones, two in the 
proximal series answering to the tibia and fibula, and one in the 
A RY, Mn ee ee Ee 
