1890.] Zoölogy. 485 
In 1830 Wagler establishes the genera: Rhinemys, Hydromedusa, 
Podocnemis, Platemys, Phrynops, Pelomedusa. 
Rhinemys contains the species: Emys rufipes, Spix., Emys nasuta, 
Schweigg, Emys radiolata, Spix., Emys, gibba, Schweigg. The type 
of Rhinemys is n a de atte Schweigg. Itis now proper to examine 
whether Am Spix., is generically different from Emys geoffroyana 
Schweigg ; in othe? words, whether Phrynops is different from Rhine- 
mys. Through the great kindness of Prof. R. Hertwig, of Munich, I 
have received the skull of the type of Amys rufipes Spix. for examina- 
tion. The skull is characterized by the very much expanded parietals, 
which are twice as broad as the interorbital space. 
In Lmys geoffroyana Schweigg, the type of Phrynops, the parietals 
are not so much expanded, but in all other respects Phrynops agrees 
with Rhinemys, and there can be no doubt that Phrynops is not differ- 
ent generically from Rhinemys. 
The type of Rhinemys Wagler is behind rufipes Spix; the other 
species of Rhinemys are: RA. hilarit, Rh, tuberosa, Rh. geoffrayana, 
Rh. gibba, Rh. seater i wagleri. Boulenger’s Hydraspis is there-* 
fore synonym of Rhinem 
2. Js Boulenger's Hess generically different from his Hydraspis? 
In Rhinemys of Boulenger, with the single species RA. nasuta, the 
parietals have become very slender; in other words the reduction, 
which has already begun in some of the species of Rhinemys mihi 
(Hydraspis, Blgr.) has increased. This, and also the slenderness of 
the parieto-squamosal arch, is certainly no reason to distinguish this 
form as generically different from the others. According to Boulenger 
there are only four neural plates in his Rhinemys, six in his Hydraspis, 
but the question is, whether the number is constant in Hydraspis ; the 
number in Rhinemys rufipes and Rh. wagleri is not yet known. Of 
course there is no doubt that if Boulenger’s Rhinemys should even 
prove to be different generically from his Hydraspis, the name Rhi- 
nemys could not be used, and another name must be given. I think 
it best to consider Emys nasuta of Schweigg as a species of the 
genus Rhinemys Wagler, as adjusted by me. 
I give now the following synomy : 
CHELODINA Fitz., 1826—-Hydraspis Bell, 1828. 
Type Ch. longicollis Shaw. 
Ruinemys Wagler, 1830-—-Phrynops Wagler, 1830-=Hydraspis 
(Bigr.)+ Rhinemys (Blgr.), 1889. 
Type, RA. rufipes, Spix. 

—G. Baur, Ph.D, 
