270 HAY—EXISTING GENERA OF THE TRIONYCHID#. [Oct. 2, 
Dr. Baur, in the paper referred to, concludes that inasmuch as the 
species cartilagineus (javanicus') was fully figured by Fitzinger, it 
is the one to be regarded as the type of Aspidonectes. In coming 
to this conclusion he does not give due weight to what Fitz- 
inger himself, in 1843, has done in the case; much less has he 
noted what Bonaparte had donestill earlier. In Wiegmann’s Archiv 
fiir Naturgeschichte, iv, 1, 1838, pp. 136-142, we find a paper by | 
C. L. Bonaparte, entitled ‘‘Cheloniorum Tabula Analytica.’”’ In 
1836 the same author issued at Rome a pamphlet of ten pages 
which bore the same title. This is understood to be a reprint from 
the Giornale Arcadico. I have not been able to see either the 
paper in the Gzorna/e or the reprint, but Dr. Theodore Gill kindly 
informs me that the reprint made at Rome differs-in only unimpor- 
tant respects from the paper in the Archiv fiir Naturgeschichte. 
We find therefore, in this paper of 1836, that Bonaparte accepts 
two genera of Trionychide, Amyda and TZyionyx, with four 
divisions under the former. With each of his names he mentions 
a single species, and these species, it seems to the present writer, 
must be regarded as the types of these subdivisions, all later treated 
as genera. Under Zrionyx he mentions Zestudo granosa; under 
Aspidonectes, Trionyx triunguis (egyptiacus); under Platypeltis, 
Testudo ferox; under Pelodiscus, Aspidonectes sinensts, and under 
Amyda, Trionyx subplanus. 
In 1843, Fitzinger (Systema Reptilium, p. 30) presented essenti- 
ally the same arrangement of the Trionychidz that Bonaparte had 
published in 1836. His two genera are Zrtonyx and Aspidonectes, 
the latter having under it five subdivisions, or subgenera, For 
Trionyx, Aspidonectes, Platypeltis, Pelodiscus and Amyda, he 
employed the same species as examples, or types, as did Bonaparte. 
For the newly proposed subdivision Potamochelys he used as type 
P. cartilagineus (javanicus). Dr. Baur made the objection that 
Fitzinger did not define the genus Potamochelys ; but since the lat- 
ter author refers to it a well-known species, it must be accepted as a 
valid genus, in case it really possesses generic characters. That is, 
technically it meets all the requirements of a generic name. 
It may be noted here that Fitzinger’s error of 1836, in distributing 
the species ¢riumguis, under the names @gyptiacus and labiatus, to 
1In the present paper the specific name now recognized is employed; if the 
author who is quoted employed a different name, this follows in parentheses, 
