74 MESSRS. MURIE AND MIVART ON THE 
Delineated in Galago crassicaudatus (PI. II. fig. 3, Pl. V. fig. 19, and Pl. VI. fig. 25, 
S.mb). Substantially it is the same in G. allenit as in L. catta, but it does not arise 
from the ascending ramus of the ischium. 
In Nycticebus, Tarsius, and Cheiromys it is nearly as in L. catta. 
SemrrenprNosvs '.—Arising in common with the biceps from the outer margin of the 
tuberosity of the ischium, and also in great part from the tendon of origin of the last- 
mentioned muscle, it is inserted into the tibia in common with the gracilis. It has no 
origin from the caudal vertebree. 
In Cuvier’s representation of Lemur varius, pl. 70. fig. 2, 7, the distal part of this 
muscle is represented as bifurcating, the larger portion joining the gracilis as usual, 
but the smaller portion passes to the outside of the leg in conjunction with the biceps. 
In Galago crassicaudatus (Pl. Il. fig. 3, Pl. V. fig. 19, and Pl. VI. fig. 25, S.t). 
In Cheiromys, according to Professor Owen’, this muscle is double, having an 
additional slip arising from the second caudal vertebra adjoining the caudal origin of 
the gluteus. Our observation confirms this statement. 
c. Tibio-fibular Region of Leg (extensors). 
Tisrauis ANTICUS*:—This muscle is quite single, and only of a moderate size. It arises 
from the upper two-thirds of the peroneal surface of the tibia, as far back as the 
interosseous membrane. Its insertion is into the anterior end of the tibial margin of 
the entocuneiform, and not at all into the metatarsal of the hallux. Part of the outer 
border of this muscle is in contact with part of the inner margin of the peroneus 
longus. 
L. varius, L. xanthomystax, and L. nigrifrons (Pl. VI. fig. 27, 7.a’, T.a*) possess what 
may be considered a double tibialis anticus muscle. The larger portion or division 
(T.a') answers to the condition above described in L. catta. The smaller portion (7.a*) 
has an origin along with the larger one, but superficial and perinead to it. Its small 
but distinct belly gives origin, at its lower end, to a slender tendon which is inserted 
into the plantar surface of the proximal end of the first metatarsal. This tendon runs 
in the same groove as the other part of the tibialis anticus proper, and lies in front 
of it. 
In Galago crassicaudatus (PI. II. fig. 3, Pl. V. fig. 22, and Pl. VI. figs. 25 & 29, T.a), 
G. garnettii, and G. allenii it is very large and broad. Its relations to the peroneus 
longus, peroneus brevis, and extensor longus digitorum, as well as insertion, are the 
same as in L. catta. 
There is no division in Loris gracilis or in Nycticebus tardigradus*. 
‘ Figured by Cuvier in Loris gracilis, pl. 67. fig. 2,7; by Burmeister in Tarsius, p. 74, tab. 3. fig. 1. no, 21. 
> Loc. cit. p. 65, pl. xxv. fig. 1, a. 
> Figured by Cuvier in Z. varius, pl. 70. figs. 1 & 3,6, and in Loris gracilis, pl. 67. fig. 1, é. 
* P.Z.8. 1865, p. 249. 
