32 Mr. W.S. Mactreay on the Comparative Anatomy 
and Peacock. In both orders the sense of hearing is much 
developed. In both orders we find animals, such as Squirrels 
and Pigeons, with their toes perfectly free ; and others, as Hy- 
dromys and Phasianus, which have them united at the base by a 
membrane. Castor is an aquatic animal, having some relation 
to Cetacea; Struthio is a terrestrial animal, approaching to Na- 
tatores. And so on relation comes so fast upon relation, that I 
know not how we can for a moment hesitate to place the Glires 
opposite to the Rasores. 
I conceive it now to be demonstrated, that, so far as relates to 
the analogies existing in nature between the orders of Mammalia 
and Aves, we ought to place them thus: 
Animals typically. 
1. Perm’) 25% 2%. CAYNIVOLOUS ~ We ele es ee 1. Raprores. 
2. PRIMATES. ...-.. Gmoiver@Olris oad 4 0.6 oO > Sc ond 2. INsEssorEs. 
Sr GUIRES c hetle sis): ATU PHVOLOUS| <p sg) ie) =| 10 ie eee) (alesis 3. Rasorgs. 
4, UNGULATA..... frequenting the vicinity of water. . . 4. GRaLLaTorgs. 
5. CETACEA...... AQUALICH ays elves! +) fel hs “opolta) 1s] “o) 1 Nolte 5. Navatores. 
The above series of Mammiferous orders is only adapted ana- 
logically to that of Birds, as given by Mr. Vigors*, and founded 
by him on relations of affinity. I now, therefore, come to the 
examination of the second subject; namely, ‘The Connection of 
the above Orders of Mammalia in their own Series of Affinity. 
And commencing with the Primates, as the universally acknow- 
ledged point of departure, I find Hermann in 1783 writing of 
Monkeys as follows :—*‘ Ex alter4 parte minutissime istee Ame- 
ricane et delicatulz species quas Sagoinos vocant, unguibus acu- 
tioribus et magis in arcum curvatis, mintriente voce et omnia ar- 
rodendi instinctu, ips4 demim corporis exilitate Glirium familiz 
sunt contermine. Sienim a S. argentate capite recedas, nonne 
* Linn. Trans. vol. xiv. p. 406. 
et 
