1899.] THE MYOLOGY OF THE EDENTATA. 1001 



inserted into the hallux. In the Mnnidce (29, 32) the same 

 descfiption applies, but in one case (32) a small slip was given to 

 the second toe as well as to the first. Ln the Ori/cterojyodidce (35, 

 36) the muscle rises rather higher up from the fibula, and in both 

 cases had a slip of communication with the extensor longus 

 digitorum. 



Extensor longus digitorum. — In the Bradgpodidoe, Brad,i/pus (1, 

 2, 4) and Choloepus (8, 9) have the usual origin from just above 

 the external condyle of the femur ; but in Meckel's specimen of 

 Bradgpus (4) tibial and fibular origins were also met with. In 

 Bradgpus the insertion is never into the toes. In our specimen (1) 

 the tendon divided into two slips, which were inserted into the 

 bases of the innermost and outermost of the three developed 

 metatarsal bones ; it will be observed that the outermost of these 

 is the same muscle as the human peroneus tertius. Cuvier and 

 Laurillard's figure agrees very closely with our specimen, though 

 they call this part of the muscle the peroneus brevis (6). In 

 Humphry's specimen (2) the whole muscle was apparently 

 inserted into the outermost metatarsal, while in Meckel's (4) it 

 went to the innermost. In Chohepus the insertion may be into 

 the dorsum of all thx'ee toes (8, 10), or only into the second and 

 third (9). Among the Mgrmecopliagidre, the origin is condylar in 

 Mgrmecophaga (11) and Tamandua (14), but in Cgclotharus it rises 

 from the tibia only (17, 19), or the tibia and the fibula (20). The 

 insertion is usually into the four outer toes, though in Cuvier and 

 Laurillard's figure (21) it appears as if slips only went to the third 

 and fourth toes, and in Couvreur and Bertaillon's specimen of 

 Algrmecophaga into the three outer toes. In the Dasgjjodidce a 

 femoral origin is never found, the muscle rising from the upper 

 part of the fibula only, and being inserted into the four outer toes. 

 This description applies to Dasgpms (23), Tatusia (25), and 

 Chlamgdophorns (27, 28rt). In one specimen of Dasgpas, however, 

 (22) a slip was sent to the hallux as well as the other four toes; 

 otherwise this specimen agreed with the rest. In the Manidce the 

 chief origin is from the tibia and fibula (29, 32, 33, 34), but in 

 some specimens (32, 34) a feeble femoral origin is found. The 

 insertion is into the outer three (29, 33) or four (32) toes. In 

 the Orgcteropodida' (35, 36) there is the normal femoral ori<Tin, 

 and the insertion into the four outer toes (35, 36, 37). We have 

 already drawn attention to the connection with the extensor 

 proprius hallucis. 



Extensor brevis digitorum. — In the Bradgpodidce this muscle 

 usually rises from the lower end of the fibula (1,4, 6), but sometimes 

 from the tarsal bones (presumably calcaneum) (2). It generally 

 sends shps to all three toes (1, 2), but in one case (4) it only sent a 

 tendon to the inner toe. In Chohepus (8, 9, 10) the muscle always 

 rises from the tarsus and is inserted into the long tendons of all the 

 toes. In the Mgrmecop)hagidce the muscle always rises from the 

 tarsus. In Mgrmecophaga (11) and Tamandua (14, 15) it sends slips 

 to all five toes, but in Ggdothurus (17, 19, 20, 21) only to the four 



