CONTRIBUTIONS FROM THE ZOOLOGICAL LABORATORY OF 
THE MUSEUM OF COMPARATIVE ZOOLOGY AT HARVARD 
COLLEGE. E. L MARK, DiRECTOR. No. 118. 
CORRELATED, ABNORMALITIES IN THE SCUTES 
AND BONY PLATES OF THE CARAPACE OF 
THE SCULPTURED TORTOISE: 
G. H. PARKER. 
A TYPICAL carapace of the sculptured tortoise (Chelopus 
insculptus LeC.) is composed of fifty bony plates, so united as 
to form a strong dorsál shield, and of thirty-eight horny scutes 
covering this shield ex- 
ternally. These ele- 
ments are arranged as 
shown in Fig. 1, in which 
the black lines represent 
the limits of the bony 
plates, and the lighter 
ones those of the scutes. 
The scutes form three 
series: first, a median 
set, which, beginning at 
theanterior end and pro- 
ceeding posteriorly, con- 
sists of a narrow nuchal 
scute, five large central 
scutes, and a pair of 
pygal scutes, one right 
Fic. 1. — Dorsal view of a normal carapace of a male 
and the other left 5: SEC sculptured tortoise. The faint whitish lines represent 
; the edges of the scutes, which were removed in making 
ondly, four pairs of large the preparation; the black lines mark the margins of 
centro-lateral scutes, '"e*ony Plates. xi 
which flank the median series, except at the anterior and the 
posterior ends ; and, thirdly, eleven pairs of marginal scutes, 
17 
