SP a ae ae. it 
Toy ge a 
1886. } Geology and Paleontology. 967 
Revue Scientifique, Vol. xxxi, p. 705. But these relations had 
been previously pointed out by myself; that of Hyracotherium 
in the Paleontology of the Report of the Survey W. of the 100th 
meridian in 1877; and that of the Phenacodus in the Proceeds. 
Amer. Philos. Soc., 1881, p. 178!—E. D. Cope. 
Dotto on Extinct Torrotses.— The distinguished Belgian 
anatomist, M. Louis Dollo, has recently published two important 
Papers on extinct tortoises from the Eocene formations of Bel- 
gium. The theme which gave rise to the first of these, is the de- 
scription of a new genus and species of Chelydride, Pseudo- 
trionyx delheidi Dollo. In preparing to do this, the author re- 
Views the classification of the Testudinata in an extremely 
able manner. He adopts the system of Cope in the main, 
and in giving his reasons for doing so makes an important 
contribution to the subject. He differs in some details from the 
author of that system. Thus he separates Eurysternum from 
the Chelydridz as type of a distinct family, because it possesses 
a fontanelle of the plastron ; a character which the reviewer does 
not regard as of family value. He also unites the Propleuride 
with the Cheloniidz, but as we shall see, he reéstablishes it as a 
sub-family in the second paper quoted, without apparently being 
aware of the fact. 
- Dollo somehow supposes that the author of the system he 
adopts regards the plastron of the Testudinata as homologous 
with the sternum of other Vertebrata, and also that the names he 
employs for the elements of the plastron are original with him. 
This is an error. The terms “ postabdominal,” etc., were introduced 
by the distinguished English anatomist, W. K. Parker, and the au- 
thor criticised by M. Dollo, has stated in one of his papers, on 
Which I cannot at this moment place my hand, that he adopts the 
views as to the homologies of the plastron, held by that authority. 
But M. Dollo thinks that the names Dactylosterna, Clidosterna 
and Lysosterna imply the erroneous homology with the sternum, 
and should therefore be charged. He then names thesedivisions 
ctyloplastra, etc. Now names ought not to be changed without 
tter reasons than those offered by M. Dollo, for the well-known 
Pprobrium scientie is the multitude ofnames. Those in question 
Were not given under an erroneous idea, but the word “ sterna’ 
Was used figuratively, just as it is in many genera of the order. 
As well might M. Dollo change the generic nam 
x es Eury- 
. Sternum, Pleurosternum, etc., into Euryplastron, Pleuroplastron, 
etc. And this our author has not yet done. 
_ The plates called intergular by me in Baéna appear to me to be 
3 _ A0mologous with the corresponding plates in Pleurodira, although 
? Also in NATURALIST for 1881 
: p- 1O17. : 
3 iére note sur les Cheloniens du Bruxellien de la Belgique; (Bull. Mus. 
Roy, Belgique 1886, p- 75)- Premiér Note s. 1. Cheloniens Landeniens de la Bel- 
que; (1. c. 1886, p. 129). 
t 
