TAXEOPODA. 



379 



II. Proboscidea. 

 There may be two sub-orders of this order, the Proboscidea and the 



Toxodontia. I do not know the carpus of 

 Toxodon, but if it does not differ more from 

 that of the elephants than the tarsus does, it 

 is not entitled to subordinal distinction from 

 the Proboscidea. The sub-order of Probos- 

 cidea is defined as follows : 



A fibular articulation of the calcaneum ; uo post- 

 glenoid process; no third trochanter of femur 



Proboscidea. 



III. Amblypoda. 



The sub-orders of this order, as I pointed 

 out in 1873, are two, defined as follows: 



Superior incisor teeth; no ali-sphenoid canal; a 



Fig. 18.-Po8terior foot of Coryphodon ^j^j^.^, t.oehanter of femur ranU,(lonia. 



(original). From Capt. G. M. Wheelers ._ ... ,.,.-, 



Report Snrv.w. of 100 Mer.,iv. Cue-third ^o Superior incisors, nor ah-sphenoid canal, nor 



natural size. third trochanter of femur Dinocerata. 



The difference between the Proboscidea and the Amblypoda consists 

 chiefly in that the navicular of the latter is short- 

 ened externally so as to permit the cuboid to artic- 

 ulate with the astragalus. The cuboid has the same 

 form in botli. The peculiar character of the navicu- 

 lar gives the astragalus a different form. 



IV. DiPLARTHRA. 



This order is called bv some authors the Un- 

 gulata, but that name is also used in the larger sense 

 in which it is here employed. This appears to be 

 its legitimate application, as the name should, if pos- 

 sible, be used for hoofed Mammalia in general, as its 

 meaning implies. The two well-known sub-orders Fig. i9.^— Left pes of Eie- 



,1 /. n . »Aas indiciiS one-tenth natural 



are the following : fi^^ . ^^^^^ ^^^^^^ 



Astragalus truncate distally ; number of toes odd, the median the largest . Pemso</rtc<y/fl. 

 Astragalus with a distal giuglymus ; number of toes even, the two median largest. 



Artiodactyla. 



