282 MESSRS. B. C. A. WIXDLE AND F. G. PARSONS ON [Nov. 3, 



Flexor tibialis {Flexor longus digitorum of human anatomy). — 

 This rises from the upper part of the posterior surface of the 

 tibia, and from the back of the head of the fibula just below 

 the popliteus. In every case of which we have records it joins 

 the flexor fibularis in the upper part of the tarsus. As a rule it 

 only sends fibres to the tibial digits, while the flexor fibularis 

 supplies them all. In the Elephant and Camel, however, the 

 flexor tibialis is the larger tendon of the two. Like the flexor 

 fibularis it is supplied by the posterior tibial nerve. 



Lttmbricales. — Speaking generally, the Ungulates are not well 

 provided with these muscles. In the Hippopotamidse, Gratiolet 

 (III.) found one for the medius digit. In the Suidas they are 

 apparently absent, at least they were so in our specimens (11,14), 

 and we find no mention of them by other writei'S, nor are they 

 drawn in Cuvier and Laurillard's plates (I.). In the rest of the 

 Artiodactyla they are, we believe, always absent. In the Perisso- 

 dactyla they are more constant. Ohauveau (II.) describes two in 

 the Horse, one from each side of the flexor perforans tendon. In 

 the Tapir (61, 62) there are three, the outermost being much the 

 largest. Among the Subungulata, Hyi-ax (74, 75) has two, which 

 pass round the tibial sides of the medius and annularis digits ; 

 in our specimen (75) they were both supplied by the external 

 plantar nerve. In the Elephant, Paterson and Dun found only 

 one small lumbrical, which was on the tibial side of the medius 

 digit and was supplied by the internal plantar nerve. Miall a.nd 

 Greenwood (XXIX.), however, describe some more superficial 

 ones rising from the plantaris and being inserted into the plantar 

 sheaths. 



Tibialis posticus. — This muscle, when it is present, rises from 

 the upper part of the back of the tibia and joins the flexor 

 fibularis in the upper part of the tarsus before that tendon unites 

 with the flexor tibialis. We have records of it in the following 

 animals: Hippopotamus (3), Suidse (4, 7, 12, 13, 14), Camel (15) 

 — here it is said to form the chief working part of the flexor 

 perforans, — Ohevrotain (20), Water- Che vrotain (24), Axis Deer 

 (25), Ox (35, 36, 40), Sheep (41, 42), Goat (50, 51), Horse (63, 

 65). In the Elephant, according to Paterson and Dun, it rises 

 from the tibia, fibula, and interosseous membrane, and is inserted 

 into the dorsum of the bases of the second and third metatarsal 

 bones as well as slightly into the first. Miall and Greenwood 

 (XXIX.) and Anderson (XXYII.) agree with this, though neither 

 of them found any insertion into the first metatarsal, but in 

 Anderson's specimen it went to the fourth in addition to the 

 second and third. It is certainly absent or quite fused with the 

 flexor fibularis in many ungulates; thus Bronn (VI.), Meckel 

 (VII.), and Cuvier say that it is absent in the order, and in the 

 following animals it could not be made out : — Chevrotain (22), 

 Brocket Deer (29), Gazelle, Sheep (47), Duiker-bok (54), Har- 

 nessed Antelope (55), Tapir (56, 61, 62), and Hyrax (74, 75). 

 Its nerve-supply is the posterior tibial. 



