612 The American Naturalist. [July, 
: Origin of the Edentates.—Dr. Wortman has come into posses- 
sion of material which, in his judgment demonstrates the genetic rela- 
tionship of the Ganodonta to the later appearing American Edentata. 
In considering the Ganodonta the author points out the features which 
characterize the genera composing the family and which become more - 
and more marked as the respective phyla advance into later time. 
These features relate to the loss of the incisors, the weak development 
and loss of the enamel, and the development of hypsodonty with its de- 
pendent modification growth from a persistent pulp. Of one phylum, 
viz. the Stylinodontid, Dr. Wortman has remarkably complete record, 
beginning in the generalized type Hemiganus of Lower Puerco, and 
continued into the Bridger, terminating in Stylinodon. In a compari- 
son of this group with the Ground Sloths (Gravigrada) the author 
enumerates 17 points of resemblance which he considers sufficient evi- 
dence to demonstrate that the one has descended from the other. The 
next inference then is that all the South American Edentates must 
have been derived from the North American Ganodonta, since 
their earliest appearance in South America does not antedate the Santa 
Cruzepoch. But this necessitates a land bridge between North and 
South America during Eocene times, which is contrary to the accepted 
belief among geologists, In closing Mr. Wortman defines the order 
Edentata and its three suborders, Ganodonta, Xenarthra and Nomar- 
thra with their families, and distinguishes the genera of the Ganodonta. 
(Bull. Amer. Mus. Nat. Hist., Vol. IX, 1897.) 
Gypsum Deposits of Kansas.—The following information con- 
cerning the gypsum beds of Kansas was obtained by Mr. G. P. Grims- 
ley during a field investigation of the region in which they occur: 
“The gypsum beds of economic importance in Kansas are all Perm- 
ian in age, ranging from middle Permian or Neosho to the close. They 
cover a belt approximately 200 miles long, 10 miles in width at the 
north, 20 miles in central Kansas, and 60 miles in the southern part of 
the state. The deposit is 8 feet thick in northern Kansas, 14 feet in 
the central area, 25 feet in the southern area, and even thicker further 
south. `The northern and central rock gypsum was deposited in the 
same gulf cut off from the western Permian sea, while the gypseous dirt 
deposits are secondary and of recent age. The southern deposit was 
formed in a shallow bay cut off from the Permian sea, not far from the 
close of Permian time. Salt appears to have been deposited in these 
bays, but now it is only found farther out in the old gulf.” (Bull. 
Geol. Soc. Amer., Vol. 8, 1897.) 
