642 APPENDIX AND ERRATA. 
Gray is certainly mistaken in referring Emys oregonensis as synonyme to Chrysemys Bellii. Through the 
kindness of my friend, James M. Barnard, I have lately received a dozen living specimens of Chrysemys oregon- 
ensis, — or rather Nuttalii, as I would now eall it, — and feel satisfied that it is distinct from Ch. Bellii, of 
which I have also seen a large number of living specimens. They differ not only in the pattern of their color, 
but they occupy also different tracts in the western Fauna. Chr. Nuttalii is a more northern species. This 
species is inscribed in our herpetological works as Emys oregonensis; but as there is no evidence of its occur- 
rence in Oregon besides the alleged indication of Mr. Nuttal, who probably collected it on this side of the 
Rocky Mountains, where it is common in Minesota and westward to the junction of the Yellowstone and Mis- 
souri, I propose henceforth to call it Chrysemys Nuttalii, in commemoration of its distinguished discoverer. 
Should the fossil Turtle described by Pomel as Ptychemys prove to constitute a natural genus, I propose, 
for our living species, to change the name of Ptychemys to Nectemys. 
I am glad to find that Dr. Gray has himself given up the genus Onychotria, against the adoption of which 
I have raised objections, (p. 445.) It remains now to be ascertained whether the Mexican three-toed Cistudo 
differs from that of our Southern States. 
Gray describes two Cinosternums from North America as new species, founded upon young specimens. I 
confess my inability to distinguish them from Cin. pennsylvanicum; Cin. punctatum seems to me to be a young 
male, and Cin. Hippocrepis-a young female, with a rather narrow hind lobe of the sternum, as is occasionally 
the case in Cin. pennsylvanicum. I have seen such large numbers of Cinosternum pennsylvanicum, that I feel 
little doubt upon this point. It is gratifying to me to see that Gray has arrived at the same conclusion as 
I have expressed (p. 428) respecting his Cin. oblongum. As to Cinosternum scorpioides, cruentatum, Doubledayi, 
and leucostomum, I refer simply to what I have already stated p. 426, note 1, and p. 429. 
The genus Aromochelys Gray embraces the two genera which I have distinguished as Ozotheca and Gonio- 
chelys. His Aromochelys odorata is the same as my Ozotheca odorata, and his Aromochelys carinata is iden- 
tical with my Goniochelys triquetra. Gray’s genus Macroclemys is also identical with my Gypochelys. 
The British Museum must be very indifferently provided with specimens of North American Trionychide, since Dr. 
Gray has failed to perceive the generic and specific differences which exist among them, and which his extensive 
knowledge of this family would at once have pointed out to him. As it is, he confounds the southern Trionyx 
ferox with the northern spinifer, and considers Trionyx muticus as a very doubtful species. I have shown (p. 
398-405) that they belong to three different genera, and that three other species of this family, found in the 
rivers of North America, have remained unnoticed to this day. 
ERRATA IN THE TEXT: 
Page 11, 2d line, instead of I shall consider, read is to be considered. 
— 18, note, 2d col., line 10, instead of Naturwissenhaft, read Naturwissenschaft. 
== 28, eke et ce 7,1) ik McKoy, mead McCoy. 
— 29, 30th line, instead of the studies of which, read whose studies. 
— 34,18th “ jor has, read have. 
— 35, 30th “ “ is, read are. 
—41,15th “ “ insertiverous, read insectivorous. 
—43,12th “ “ amimals, read animals. 
—43,17th “ “ Betrachians read Batrachians. 
— 52, note 2d col., 8th line, instead of to deny, read in denying. 

