ANATOMY OF THE LEMUROIDEA. 61 
has a similar appearance to that described, and overlies it, the two filling the flattened 
surface between the spines and tips of the transverse processes. 
PUBO-COCCYGEUS AND IL10-coccyGEUS.—These muscles are represented by a broad, flat 
sheet of muscle arising from the sacro-iliac synchondrosis and the fascia investing the 
psoas parvus, also from the inside of the so-called “ horizontal” ramus of the pubis, as 
far as the symphysis. ‘Their united insertion is into the chevron bone placed between 
the third and the fourth caudal vertebre. 
Partly shown in Pls. II. and VI. figs. 5 & 25, and severed, excepting origin and inser- 
tion, in Pl. V. fig. 19, P. & i. ¢. 
In the Slow Loris the united representative of the above is comparatively of large 
size, though thin. It covers the obturator internus from near the pubis to the posterior 
end of the brim of the pelvis, and is inserted on the under surface of the third caudal 
element. 
The Sacro-coccyGEus arises by considerable fleshy bellies from the ventral surface of 
the bodies of all the sacral and the first five caudal vertebrae. It is continued back- 
wards between the chevron bones and transverse processes of the caudal vertebree with 
numerous long tendons, like the levator caude externus. 
Indicated in position in Galago crassicaudatus (P1. II. fig. 3, S.c), and with tendons 
apart (Pls. V. and VI. figs. 19 & 25, S.c). 
Nycticebus has this well developed and muscular; it is partly united to the internal 
sphincter ani and to the surface of the infra-coccygeus, and is inserted on the caudal 
vertebree. 
The Iscuio-coccycevus has origin from the spine of the ischium and the part imme- 
diately anterior (superior) to it, above (behind) the acetabulum. Expanding in a fan- 
like manner, it is inserted into the tail beneath the transverse processes of the first four 
caudal vertebre. 
It exhibits little or no difference in the Galagos, see Pl. VI. fig. 25, Js.c. 
It is broad and strong in the Nycticebinz, and drags the abortive tail well down- 
wards and forwards, so that this organ in the live animal almost seems absent. 
The Inrra-coccyGEvs arises by muscular fibres from the last sacral and the first five 
caudal vertebre. It connects together the chevron bones of contiguous vertebre for 
about half the length of the tail. 
In Galago it connects the caudal vertebree in the middle line below, but barely 
attains the sacrum (PI. V. fig. 19, Zc). 
The two small infra-coccygeal muscles in the Slow Loris lie close together, and appear 
as a narrow muscular riband lying on the inferior sacral surface. Tendons cannot be 
traced into the rudimentary tail. 
INTERTRANSVERSARII CAUDA.—This muscle (or series of muscles) is, as Meckel remarks 
of Ateles', of considerable size at the root of the tail. It arises from the dorsum of the 
1 Loc. cit. vol. vi. p. 179. 
