434 The American Naturalist. [May, 
but enters the roof of the brain in the region of the habenular gan- 
glion. This difference does not strike one as forcibly as a little while 
ago. The recent investigations of Keibel and Assheton have shown 
that the optic stalk is not the optic nerve, but this stalk merely forms 
the tract through which the true nervous elements grow inward from 
the retinal layer. This being the case it is easy to see that possibly in 
the case of the parietal nerve the outgrowth has been through other 
tissue. 
East African Reptiles and Batrachia.—The U. S. National 
Museum has recently received some valuable collections of Reptiles 
and Batrachia from Eastern Africa and the adjacent islands and these 
have now been studied by Dr. L. Stejneger.” Among the interesting 
facts brought out is a better knowledge of the fauna of the Seychelles. 
Wallace, in his “ Island Life,” enumerates 11 species as found in these 
islands of which five are considered as peculiar to them. To-day, 
fifteen species of Reptiles and Batrachia are known with certainty, 
plus several more doubtful, as coming from these Islands and of these 
ten are not known from any other locality. Ten of these species are 
represented in the museum collections. The new species described in 
this paper are Diplodactylus inexpectatus (Seychelles), Phe/suma ab- 
botti (Aldabra), Eremias sexteniata and E. hoehnelii (Tana River, E. 
Af), Mabuya chanlerii (Tana R.), Ablepharus gloriosus (Gloriosa Is.), 
Typhlops mandensis (Manda Is.), Simocephalus chanlerii (Manda), Caw 
sus nasalis (West Africa), Hypogeophis alternans (Seychelles). 
On the Iguanian genus Uma Baird.—This genus has been 
hitherto represented by but two specimens, and has been hence = 
little known. Professor Baird in his original description in 1852 di 
not adduce any character sufficient to distinguish it from Callisauros 
Blv., and it was not until 1866 that I pointed out that the difference 
consists in the possession by Uma of a series of elongate free scales n 
each side of the digits, and on the external side of the sole, which arè 
wanting from Callisaurus. I noted the occurrence of the genus a 
Tucson, Arizona, as represented by a second and adult individua! ; 
` the type, a young animal, having been taken on the Mojave jonn i 
Since that time no additional material has come under my © 
tion. hat 
A renewed examination of these two specimens has shown me 
they belong to two very distinct species. I accordingly name the 
"Proc. U. S. Nat. Mus, XVI, 711, 1893. 
