84. Dr. C. Collingwood on Recurrent Animal Form, 
aberrant animal, falsely called the Flying Squirrel (Galeopithe- 
cus), is the representative of the Order Cheiroptera, or Bats. 
Among the Pachydermata are some no less striking examples 
of species homomorphic with those of other Orders. Thus the 
Hyrax, an animal in structure intermediate between the Rhino- 
ceros and Tapir, a miniature Rhinoceros, as it has been called, 
yet so closely resembles the Rodentia in its outward form, that 
it was long classed with them ; and Cuvier makes the following 
remark concerning it:—‘ There is no quadruped,”’ he says, 
“which proves more forcibly than the Daman (Hyrax capensis) 
the necessity of having recourse to anatomy as a test by which 
to determine the true relationship of animals.” 
The general resemblance between the Cetacea and the Pinni- 
grade Carnivora (Seals) need only be referred to; it is made 
very distinct through the herbivorous family Manatidz, espe- 
cially the Dugong (Halicore Dugong). 
We have seen how the Loris resembles the Sloth; and on the 
other hand, the Edentate genus Bradypus (Ai) bears a singular 
resemblance to Monkeys in general, even in that particular 
which is so characteristic of them, viz. their physiognomy, while 
it has a carnivorous homomorph in the Sloth Bear (Ursus labia- 
tus), called by Pennant the Ursiform Sloth, and by Shaw, 
Bradypus ursinus. 
The Insectivora are connected through the Hedgehog (Hri- 
naceus europeus) with one of the most anomalous of animals, 
the singular Monotreme genus Echidna, which has, besides, 
other homomorphs, to be afterwards mentioned; and further 
through the Shrews (Soricide), with the Rodent genus Mus; 
and with the Carnivora by the Bulau (Gymnura Rafflesii), for- 
merly described as a Viverra. 
The Rodentia are united homomorphically with the Pachy- 
dermata by means of the Capybara (Hydrocherus Capybara), 
formerly called, from its pig-like appearance, Porcus fluvia- 
tilis (Fermin), Thick-nosed Tapir (Pennant), Cochon @eau 
(Desmarchais), and Sus maximus palustris (Barrére). By the 
Flying Squirrel (Pteromys) they claim some homomorphie affi- 
nity with the Cheiroptera; but their chief homomorphism is _ 
with the Marsupialia, and most striking are the resemblances. 
Not only do the Rodentia and Marsupialia bear a general 
mutual resemblance throughout, both Orders possessing that 
extraordinary development of the hinder extremities and tail 
which enables the Jerboas, in common with Kangaroos, to take 
such wonderful leaps, but there are particular animals in both 
Orders which bear a most remarkable resemblance to one an- 
other. Thus, the Rodent Jerboas (Dipus) are closely imitated 
by the Tufted-tailed Rat-Kangaroo (Hypsiprymnus penicillatus, 
