DR. A. GUNTHER ON GIGANTIC LAND-TORTOISES. 
269 
5. A skull of a very large example, described and figured by Dr. Gkay as T. pla- 
niceps (1. c.). 
The. carapace of this species is well characterized by its broad, circular shape, great 
depth, and more especially by the numerous, deeply cut concentric striae, by which the 
areolae are much reduced in size in immature examples, and which are persistent in 
considerable number even in specimens of the largest size. Our largest example 
(specimen No. 1, Plate 33. fig. B) is a carapace 41 inches long, unfortunately without 
the sternum. Nevertheless we can safely affirm that this individual was a male, all 
observers agreeing in that the females do not attain to so large a size. It is only 
8 inches longer than broad, and when measured over the curvature its transverse 
circumference even exceeds the longitudinal. The areolar portions of the dorsal and 
marginal plates are perfectly smooth and raised above the general outline of the shell, 
especially those of the former ; but each plate has a broad margin deeply sculptured 
with concentric and parallel striae, the outer striated margin of the marginal plates being 
even broader than the smooth areolar portion. The first dorsal scute and the anterior 
half of the second are declivous, the declivity of the former being still steeper than that 
of the latter. 
A deep notch, nearly as deep as that between the two foremost marginal plates, exists 
between the first and second marginals ; and also the posterior margin of the shell is 
scalloped. The length of the caudal plate is to its width as 11 : 14 (5-| inches long and 
7 inches wide) ; its surface is plane, that is, its posterior margin is not bent either 
inwards or outwards. The general colour is a deep black, with a brownish tinge about 
the margins of the majority of the plates. 
As in the preceding species, the shell is thin and light ; in this specimen it is only 
4 millims. thick in the middle of a costal plate. Specimens of the common Testudo 
grceca only about 8 inches long have a carapace almost as thick as these gigantic 
Tortoises. 
The second specimen (Plate 35. fig. C), which is 22 inches long and the type of T. 
nigrita, is young, and probably a male, inasmuch as the sternum shows a slight con- 
cavity, and the passage between the hind margins of the caudal and sternal plates is 
of inconsiderable width. As in specimen No. 3 (15^- inches long), the carapace is 
deeply sculptured all over, the smooth areolae being very small. Its transverse circum- 
ference equals the longitudinal. The front margin, as well as the hind margin, is 
deeply notched, each notch corresponding to the suture between two marginal plates. 
The outer surface of the caudal plate is convex, the hind margin being curved inwards ; 
its length is to its width as 3 : 4. The sternum terminates anteriorly in a thickened, 
rounded, double-headed transverse knob, with a slightly concave surface below; and 
posteriorly in a deep rectangular notch. The colour is the same as in the adult example. 
Our very young example, which is only 8^ inches long, and figured in Proc. Zool. 
Soc. 1. c., agrees in every respect with those of more advanced age, differing from young 
mdccclxxv. 2 o 
