THE GIGANTIC LAND-TORTOISES OF MAUEITIUS. 49 
one (No. 39953), both of the right side, have the shaft rather smooth, subtetrahedral, 
with a large tuberosity on the posterior surface in the middle of the length. The semi- 
lunar facet for the articulation with the humerus is comparatively narrow (40 : 21). 
b. A third radius (No. 39952) agrees with the first two in the shape and smoothness of 
the shaft, which, however, is a little more slender. The tuberosity occupies also the 
same place ; but the semilunar articular facet is conspicuously broader and shorter 
(37:23). 
c. The fourth radius (No. 39951) is of the left side of a large individual, and dis- 
tinguished by rough crests and protuberances, especially in its lower fourth. Its shaft 
is more compressed, and the tuberosity on its hinder surface placed above the middle 
and connected by a strong ridge with the lateral facet for the articulation with the 
ulna. The semilunar articular facet has nearly the same form as in the first tjpe 
(39 : 21). 
Measurements. 
No. 39950. No. 39953. No. 39952. No. 39951. 
millim. millim. millim. millim. 
Length of radius 127 97 125 132 
Circumference in its narrowest part 53 32 47 52 
Longitudinal diameter of semilunar facet 40 24 37 39 
Transverse diameter of the same 21 13 23 21 
Pelvis. — The two collections contain nine perfect specimens, and fragments of as 
many other individuals, referable to three distinct types : — 
a. Seven out of the nine perfect specimens belong to a type (Plate XXVI. fig. A 
and Plate XXVIIL fig. C) which is distinguished by the short vertical and long hori- 
zontal diameter, thus aff"ording sufficient ground for associating it with that low cara- 
pace which has been referred to T. triserrata. The male and female specimens of this 
type can be clearly recognized by the great difference in size. The ossa ilii are short 
and broad, far apart, so that the vertical diameter of the pelvis does not much exceed, 
or may be even shorter than, the horizontal. A strong ridge rises from the middle of 
the outer surface of the bone and ascends to the anterior spine. The lower part of the 
pubic bones is strongly inclined downwards, concave above in the male, and slightly 
convex in the female, and emits laterally a strong process, dilated at its end and more 
or less obliquely directed outwards. The posterior part of the ossa ischii is of con- 
siderable width, sometimes concave above, always with a trenchant symphysial crest 
beneath; in one female specimen (No. 39935) it develops on each posterior corner a 
hamate process pointing outwards. The obturator foramina are comparatively narrow, 
sometimes scarcely wider than the symphysial bridge between them, which is perfectly 
fiat, without median ridge. 
In two of the male specimens (both in Mr. Newton's collection) all the ridges and 
crests are much more prominent, the edges sharper, every impression and hollow deeper 
H 
