1898.] MYOLOGY OF THE TEEBESTBIAL CABNITOBA. 165 



or so of the shaft of the tibia, and, when it is well developed, 

 encroaches on the fibula. It never has any origin from the femur 

 as is sometimes the case in rodents. When five toes are present 

 the tendon is inserted chiefly into the base of the first metatarsal, 

 though some of the fibres may go to the entocuneiform. In the 

 Pelidse and Canidae, where the halkix is rudimentary, the tibialis 

 anticus is inserted into that rudiment ; but in the Hysenidae, where 

 the hallux is quite suppressed, it goes to the base of the second 

 metatarsal bone. In many specimens the tendon or the whole of 

 the tibialis anticus is double ; this, however, appears to be an 

 individual variation and is not indicative of any family or genus. 

 For instance, Shepherd describes two tendons in Urstis americanus 

 (XX.), but this was not noticed in any other specimen of the same 

 animal. Watson says that in Hycena crocnta the muscle is double 

 halfway down (XV.); this is not the case in any specimen of 

 Hycena striata recorded. In Mustela foinn Perrin found two tibiales 

 antici (XXIX.), but in Cuvier and Laurillard's specimen (XXXI.) 

 the muscle was entirely undivided. 



Extensor proprius Jiallucis. — This muscle, when it is present, 

 rises from some portion of the upper half of the fibula, and is inserted 

 into the dorsum of the base of the terminal phalanx of the hallux. 

 The tendon closely accompanies that of the tibialis anticus, and is 

 often described as coming off from that : careful dissection will, how- 

 ever, always show that the two tendons are really connected with 

 separate fleshy bellies, although they lie in the same synovial 

 sheaths in passing the annular ligament. Among the Felidae, in 

 spite of the rudimentary condition of the hallux, the extensor 

 hallucis often persists. It was found in Felis leo (] ), F. tigris (4), 

 F. pardus (6), and F. pardalis (8); on the other hand, it was 

 absent in F. leo (2), F. pardus (7), and F. cattts (9). One of us 

 has already noticed (XLI.) that in Eodeats this muscle is more 

 persistent than the toe which it should move. When the toe has 

 disappeared and the muscle remains, the latter acquires an inser- 

 tion into the slip of the extensor longus digitorum to the second 

 toe. Among the Viverridse, the muscle is present in the following 

 animals: — Grypitoprocta (13, 14); Yiverra {\Q, 17); Vlverricula 

 (19) ; Genetta (20, 22, 23, 24), in one specimen (20) it ended in 

 an expansion to the first and second digits ; Paradoxurus (2o, 26). 

 In Herpestes the muscle was present in one specimen (29), absent 

 in another (30) (see fig. 3). In Cynictis (31) it joined the slip of 

 the extensor brevis digitorum to the inner toe. In Proteles and the 

 Hysenidse it appears to be always wanting (32, 33, 34, 35, 36, 37). 

 Among the Canidse, it is usually absent in Canis familiaris (43, 44, 

 45, 46, 48) and C. lar/opus (53), but it was found in two specimens 

 of G. aureus (50, 50 a), and in one of G. mesomeJas (51). 



In the Ursidse it has been seen in Ursus arctos (57) and U. 

 americanus (58, 62). 



In the Procyonidse it is present in the following animals : — 

 Procyon lotor (63, 64, 66), P. cancrivorus (67), Nasua (68, 70), and 

 Gercoleptes (72). In one specimen of Procyon lotor (65) AUen 



