144 Bulletin American Museum of Natural History. [Yo\. XXVII, 



CHAPTER II. GENETIC RELATIONS OF THE MONOTREMATA. 



Analysis. 



Pase 



I. Outline History of the Classification 1-i-t 



II. Reptilian characters in the integument. The Origin of Hairs . . . 145 



III. Reptilian characters in the reproductive organs. The Origin of Lac- 



tation l-t6 



IV. Reptilian, archaic, and aberrant characters in the skeleton of Mono- 



tremes, tending to separate them widely from the higher mammals 

 and collectively indicating that they are an extremely early offshoot 



of the mammalian stock 149 



V. Characters which demonstrate that the Monotremes are true mammals 1.56 



VI. Characters suggesting affinity with the Marsupials 157 



VII. Naturalness of the order Monotremata 158 



VIII. Summary of the Genetic Relations of the Monotremes 159 



I. Outline History of the Classification.^ 



1791 (?). Shaw describes the spiny anteater of New South Wales 

 under the name " Myrmecophaga aculeata." 



1795. Geoffroy refers to Shaw's species as representing a new genus, 

 "Aculeata," of Edentates. 



1798. G. Cuvier gives the generic name Echidna to "Les Fourmiliers 

 epineux." (Name preoccupied by Echidna Forster 1788, a genus of Morays) . 



1799. Shaw describes the Duck-billed Platypus under the name 

 "Platypus anatinus." The name "Platypus" being preoccupied Ornitho- 

 rhynchus Blumenbach replaced it. 



1800. "Les Monotremes " made a family of "les Edentes " by Cuvier. 



1800. "Ornithorhynchns parado.vus" described by Blumenbach. Ac- 

 cording to Gervais (1836), Geoffroy and Lamarck both considered the group 

 as forming a class bv itself intermediate between ^Mammals, Birds and 

 Reptiles. 



1803. The name "Les jSIonotremes" applied by Geoffroy to include 

 Echidna and Ornithorhynchus as an "ordre" with the following characters: 

 "Doigts onguicules; point de veritable dents; un cloaque commun, versant 

 a I'exterieure par une seule issue." (Quoted by Gill, 1903, pp. 433-434). 



Compiled chiefly from Palmer, 1904. 



