PROTOTHERIA. 



68 1 



5. Rodentia. 



Simplicidenlata. 

 Duplicidentata. 



6. Carnivora. 



Carnivora Vera. 

 Pinnipedia. 

 Creodonta (extinct). 



7. Insectivora. 



Insectivora Vera. 

 Dermoptera. 



8. Chiroptera. 



Megachiioptera. 



Microchiroptera 

 -*h~Lemuroidea. | „ . 

 10T Anthropoidea. [= Plates. 



I 



Sub-class Prototheria (Syn. Ornithodelphia), 

 Orders Monotremata and Allotheria. 



The Monotremes include the duckmole (Ornithorhynchus 

 anatinus), the spiny ant-eater {Echidna acukata), and a 

 third form resembling Echidna, 

 but often referred to a distinct 

 genus as Proechidna. These are 

 the lowest Mammals, very differ- 

 ent from all the rest, and they 

 exhibit affinities with Sauropsida, 

 and perhaps even with Am- 

 phibia. It need hardly be said 

 that they have no special affinities 

 with Birds. 



The duckmole is found in the 

 rivers of Australia and Tasmania; 

 Echidna, in Australia, Tasmania, 

 and New Guinea ; Proechidna in 

 New Guinea. 



In Ornithorhynchus the skin 

 is covered with soft fur ; in 

 Echidna and Proechidna there are spines among the hairs. 

 The mammary glands in the female Ornithorhynchus open 

 on a flat patch; in Echidna, in a depressed area around 

 which a temporary pouch seems to be developed. There 

 are no distinct mammas. 



Fig. 297. — Pectoral girdle of 

 Echidna. — From Edinburgh 

 Museum of Science and Art. 



sc, Scapula; cl. t clavicle; ucl. t 

 interclavicle ; co., metacoracoid ; 

 c.co., epicoracoid ; st., sternum. 



