EPICONDVLAR FURAMl N A 



39 



the former is alone concerned with the glenoid cavity. It must 

 therefore, one would suppose, correspond to the " coracoid " of the 

 Monotremata, while the upper piece of bone is the epicoracoid 

 process of that mammal. The ]\Iammalia, therefore, higher as 

 well as lower, differ from the reptiles in that the coracoid is 

 formed of two bones, the exceptions being, among some other 

 extinct forms, certain of the Anomodontia, a group wdiich it will 

 be recollected is the nearest of all reptiles to the mammals. 



The Fore-limb. — The humerus is of varying length among 

 mammals. A feature which it sometimes shares with the humerus 



Fig. 30. — Distal extrem- 

 ity of the luimerus to 

 sliow Ej)ieon(lylar Fora- 

 mina. A, In Hatteria ; 

 B, ill a Lizard {Lacerta 

 (icellata) ; C, in the 

 Domestic Cat ; D, in 

 Man. c.e, E.xternal con- 

 dyle ; c.i, internal con- 

 dyle. In A the two 

 foramina are developed 

 (at i, the entepicondy- 

 lar ; at /;', the ectepi- 

 condylar). The only 

 (-■anal (f) present in tlie 

 Lizard (B) is on the 

 external ulnar side, in 

 the cartilagiiions distal 

 extremity. In Man (D) 

 an entepicondylar pro- 

 cess [ijr) is sometimes 

 developed and con- 

 tinned as a fibrous Land. 

 (From Wiedersheim"s 

 .1 Hatomy -of Man. ) 



of lower forms is the presence of an entepicondylar foramen, a 

 defect of ossification situated above the inner condyle of that bone 

 which transmits a nerve. The same foramen and an additional 

 ectepicondylar foramen are found in the ancient reptilian type 

 Hatteria (Sphenodon) ; it occurs also in the Anomodont reptiles. 

 It is as a rule only the lower forms among mammals which show 

 this foramen ; thus it is present in the Mole and absent in the 



