222 Di. J. E. GRAY ON THE TORTOISES. (Mar. 11, 
1. CALLINIA MICROCEPHALA. 
Potamochelys? microcephalus, Gray, P. Z.S. 1864, p. 87. 
Hab. Sarawak (Wallace). 
2. CALLINIA SPICIFERA. 
Trionyx spiciferus, Lesueur, Mém. Mus. xv. p. 258, t. 15. 
Trionyx ferus, Holbrook, Herp. N. A. ii. t. 1. 
Tyrse argus, Gray, Knowsley Menag. t. 
Hab. North America. 
14. BarKIEra. 
In the “ Revision of the species of Trionychide,” in the P. Z.8. 
1864, p. 95, I figured the skull of an African Trionychid with 
a very broadly dilated concave alveolar surface to the jaws, which 
[ considered might perhaps be the adult state of the jaws of Cy- 
clanosteus senegalensis. In my paper on the genus Tetrathyra, 
in the Society’s ‘ Proceedings’ for 1865, I thought that it might 
perhaps be the skull of the Trionychid which I then described 
under the name of Tetrathyra. Since that time I have been able 
to examine the skull of a young Trionychid from Africa, which has 
the broadly expanded alveolar surface of the adult skull that I figured. 
This shows that the form of the alveolar surface does not depend 
on the age of the specimen, and that it is the character of an ad- - 
ditional genus, which I have named after Dr. Balfour Baikie, from 
whom we have received so many species from Central and Western 
Africa. 
Unfortunately there are only skulls of adult and a specimen in 
spirit of a young.animal of this species ; so that we do not know the 
form and number of the sternal callosities, especially those of the 
adult form. TI suspect that the thorax in the British Museum, 
received with the jaws, may be that of an adult animal; but 
there is no material to show that this is the case. If it is, the ster- 
nal callosities are as in Cyclanosteus with some smaller additional 
ones in front, as in the specimen figured as Cyclanosteus senega- 
lensis, var. callosa, Gray, P. Z.S. 1865, p. 424, f. 1. 
Ba1ktEA ELEGANS. (Plate XV. fig. 2.) 
The young specimen in spirit has the back of the thorax dark 
olive-brown with large yellow spots, which are somewhat similar 
but not quite symmetrical on the two sides of the central keel ; 
and there is a series of large but smaller square or roundish yellow 
spots on the margin. The sternum and under surface of the 
margin blackish, with yellow spots, and a narrow yellow edge to the 
lobes of the sternum. The underside of the shield is varied with 
yellow on the edges. Head grey-brown, white-spotted. Thorax 
white. 
The young specimens of Cyclanosteus senegalensis in spirit are 
known from those of Batkiea elegans by having the white spots on 
the crown and sides of the head nearly of the same size; in B. ele- 
