278 
TEKTJAJIY VERTEBKATA OE TJIE EATDM. 
Testudo ammon, Andrews. 
[Plate XXIV. ; text-figs. 88-90.] 
IlM),'). 'I'estiulo ammon, C. W. Andrews, A Prcdiininnry Notice of a Land-Tortoise from the Upper 
Eocene of the Fayhm, Egypt (description) : Survey Dept., Cairo (with 
a Note on the Method employed in Excavation, Strengthening, and 
Transi)ort, by 11. J. L. Eeadnell). 
I'dOl. ,, ,, C. W. Andrews, Ueol. Mag. [5] vol. i. pp. .527-530, pi. xvii. 
lype Specimen . — A nearly complete, sliglitly distorted shell, probably of a male 
(described and figured, luc. cit.; also text-figs. 88, 89); Geological Museum, Cairo. 
In this species the carapace is highly arched, the areas covered by the costal shields 
being strongly convex. The antero-lateral and posterior marginals are strongly 
everted ; there is a small nuchal shield. In the plastron the epiplastra are prolonged 
forwards in the middle line into an abruptly truncated projection (at least in the 
males). The posterior end of the plastron is notched in the middle line, and the areas 
covered by the anal plates are sharply defined by deep grooves and notches. 
Form. & Loc. — Fluvio-marine beds (Upper Eocene) : north of'I3irket-el-Qurun. 
A considerable number of niore or less nearly perfect shells of this species have been 
collected, but at {present little is known about the rest of the skeleton. Some humeri, 
a part of the femur, and some other scattered remains of a large Chelonian may be 
referred to it, and a nearly complete pelvis has been found in actual association with 
the shell : of the skull nothing is known. 
The carapace is strongly arched in all directions, and, looked at from above 
(text-fig. 88, A), it is somewhat quadrate in outline, owing to the eversion of the 
marginals at the postero- and antero-lateral regions. The areas covered by the three 
middle vertebral shields [v. 2-4) form prominent conve.x bosses, separated from one 
another and from the costals by deep grooves. The anterior border of the shell 
is notched in the middle line and somewhat upturned; there is a small nuchal 
shield T'he area covered by the last vertebral shield is strongly convex, as also 
is that covered by tlie single ])ygal shield (^u/.). In this latter region the shell forms a 
strong arched covering for the tail, ])rojecting below tbe level of the rest of the margin. 
The form of the bones of the cara[)ace will be best understood from the figures 
(IT. XXIV. fig. I A ; text-fig. 88, A). The neural bones {N. 1-7) vary considerably in 
form ; thus in the sjmeimen figured in text-fig. 88 the first is quadrate, tlie second 
octagonal, the third quadrate, the fourth and fifth hexagonal, with the shorter of the 
lateral faces in front, the sixth octagonal, and the seventh (piadrate. It appears, 
however, that in the form of the neural bones a considerable range of variation in 
different individuals occurs (see IT. XXIV. fig. 1 a). 'Ihere arc three l)ygals {Fy. 1-3), 
which, as already mentioned, form a strongly convex ])rotection for the tail. Anteriorly 
