672 The American Naturalist. [July, 
Fishes.—Evermann has revised* the North American Suckers of 
the genus Pantosteus and recognizes the species plebeius, virescens, 
generosus, discobolus and a new species jordani from the upper 
Missouri Basin. 
Reptiles and Batrachia.— Cope catalogues? eight species of Batra- 
chia, 5 of turtles, 8 of lizards and 13 of snakes collected in northwest- 
ern Texas. The region appearsto beinteresting as the meeting ground 
for several geographical districts. The absence of Sceleporus from the 
collections is due to the absence of timber. 
Davenport records the persistence? of the right root of the subverte- 
bral artery in an alligator 28 cm. long, and figures two cases of the 
persistence of the ductus botalli in the same animal. 
Mammalia.—At a meeting of the London Zoological Society, M. 
Tegetmeier exhibited the feet of some Australian rabbits to show an 
adaptation which is gradually being brought about to a new mode of 
locomotion. The rabbits are becoming climbers, and often ascend 
trees in their search for food; their feet are growing slighter and the 
. claws longer and sharper. (Revue Scientifique, Mar. 1893.)—Mr. G. 
S. Miller reports that Zapus insignis, hitherto known only from New 
Brunswick and Nova Scotia, is locally common in the eastern United 
States. As the original description was based on three specimens faded 
by grease and age, he redescribes the species in the Proceeds. Biol. 
Soc. Washington, April, 1893. 
Notes on the Classification of the Cryptodira.—In the June 
number of the AMERICAN NATURALIST, 1890, I have given a classifi- 
cation of the Testudinata, distinguishing four sub-orders— A mphichely- 
dia, Pleurodira, Cryptodira, Trionychia. 
To-day I shall give a more detailed classification of the living forms 
of the Testudinata belonging to the Cry ptodira. 
CRYPTODIRA. 
No free nasals, a parieto-squamosal arch present or absent; descend- 
ing processes of prefrontals connected with vomer; stapes in an open 
groove, of the quadrate or covered by the quadrate behind ; pterygoids 
narrow in the middle, without wing-like lateral expansions, separating 
*Bull. U. S. Fish Comm. 1892, p. 51, 1893. 
5Proc. Phila. Acad. 1892, p. 331. 
Bull. Mus. Comp. Zoology xxiv, no. 2, 1893. 
