SYSTEMATIC ZOOLOGY—GILL. 459 
ichthyologists of France. Nevertheless the work was quite backward 
in some respects and exercised a retardative influence in that the pre- 
eminent regard in which the great Frenchman was held and the pro- 
clivity to follow a leader kept many from paying any attention to 
superior work emanating from Cuvier’s contemporaries. 
It is by no means always the naturalist who enjoys the greatest 
reputation for the time being that anticipates future conclusions. A 
Frenchman who held a small place in the world’s regard in compari- 
son with Cuvier advanced far ahead of him in certain ideas. Henri 
Marie Ducrotay de Blainville (1777-1850) was the man. When 
Cuvier (1817) associated the marsupials in the same order as the true 
carnivores and the monotremes with the edentates, Blainville (1816) 
contrasted the marsupials and monotremes as Implacentals (“ Didel- 
phes”) against the ordinary Placentals (“ Monodelphes”). While 
later (1829) Cuvier still approximated the marsupials to the carni- 
vores, but in a distinct order between the carnivores and the rodents, 
and still retained the monotremes as a tribe of the edentates, Blain- 
ville (1834) recognized the marsupials and monotremes as distinct 
subclasses of mammals and had proposed the names Monodelphes, 
Didelphes and Ornithodelphes, still largely used by the most ad- 
vanced of modern theorologists. 
Against the action of Cuvier in ranging all the hoofed mammals 
in two orders, the pachyderms (including the elephants) and the 
ruminants, may be cited the philosophical ideas of Blainville (1816). 
who combined the same in two very different orders, the Ongulo- 
grades and the Gravigrades (elephants), and distributed the normal 
Ongulogrades under two groups, those with unpaired hoofs (In- 
paridigitates) and those with paired hoofs (Paridigitates), thus 
anticipating the classification of Owen and recent naturalists by very 
many years.? 
Cuvier’s treatment of the amphibia of Linné equally contrasted with 
Blainville’s. As late as 1829 the great French naturalist still treated 
the batrachians as a mere order of reptiles of a single family, and the 
crocodilians as a simple family of Saurians. On the other hand, as 
early as 1816 Blainville had given subclass rank to the naked amphi- 
bians with four orders, and also ordinal rank to the crocodilians, and 
a little later (1822) he raised the subclasses to class rank. Still more, 
Blainville early (1816) recognized that the so-called naked serpents 
“@A more familiar instance of difference between Cuvier and Blainville is that 
involving the systematic relation of the aye-aye (Cheiromys or Daubentonia). 
Cuvier, to the end of his life, referred it to the Rodents and, in the last edition 
of the Régne Animal, interposed it between the Flying-Squirrels (Pteromys) and 
Marmots (Arctomys). Blainville, on the contrary, as early as 1816, associated 
it with the Lemurs, to which it is now universally conceded to be most nearly 
related. The evidence is very conclusive. Was Cuvier unable to appreciate its 
significance or was he too opinionated to recant a determination once formed? 
