630 
Fig. 9, from above and to the left, 26 diam. N. guttata; 
laid July 16, opened July 26, 1852. 
Fig. 9a, from above, the same as fig. 9. 
Fig. 10, from below, 20 diam. ; fig. 10a, the same as fig. 10, 
from above; (in this figure, a* should be a‘; correct 
also the same mistake in the text, p. 541, line 16 ;) fig. 
10b, the same as fig. 10a, seen more from the front; fig. 
10c, the same as fig. 10, seen directly from the front. 
N. guttata; laid July 18, opened July 27, 1852. 
Fig. 11. 
laid July 11, opened July 22, 1852. 
Fig. 12. 
guttata; laid July 18, opened July 29, 1852. 
Fig. 13. Posterior half, from below and to the left, 25 
diam. N. guttata; laid July 18, opened July 28, 1852. 
Posterior half, from above, 20 diam. N. guttata; 
Posterior half, from the left side, 26 diam. N. 
PLATE XIII. 
[Fig. 4 from nature, by H. J. Clark; the others by A. Sonrel.] 
Interior view of the egg, 
Fig. 1. the shell being taken off, 
and the shell membrane varnished ; 0, the allantoidian 
vessels; h, the upper surface of the yolk sac; 7, the vena 
afferens, 2 diam. Chelydra serpentina; laid June 18, 
opened Sept. 6, 1855. 
Fig. 2. 
indicate the direction of the currents of blood ; about 
Embryo and vascular area, from above; the arrows 
6 diam. Ch. serpentina; period of laying unknown, 
opened Aug. 3, 1852. 
Wood-cut 1, p. 553, represents parts of the same figure ; f, 
vertebre ; @, allantoidian artery, running along the side 
of the body ; 7*, abdominal or dorsal artery ; 7°, allantois. 
Ch. 
serpentina; laid June 18, opened July 10, 1855; q, point 
Fig. 3, from below, about the same diam. as fig. 2. 
from which the omphalo-meseraic arteries radiate. 
Fig. 4, 5, 6, 7, 8, 9. 
egg, with the shell partially taken off, to exhibit the ex- 
Ch. ser- 
pentina; all laid June 12, and opened July 11, 1855. 
Fig. 10, and 11. Laid June 18, and opened July 11, 1855. 
Ch. serpentina, nat. size. 
Fig. 12. Laid June 18, and opened July 10, 1855. Ch. 
(See p. 599.) 
Views in profile and from above of the 
tent of the circulation of the blood, nat. size. 
serpentina, nat. size. 
PLATE XIV. 
[Fig. 1, from nature, by H. J. Clark; the others by A. Sonrel.] 
All the figures are of Chelydra serpentina. 


Fig. 1. Embryo from the left side, about 33 diam.; laid | 
June 23, opened July 31, 1855. | 
EXPLANATION OF THE PLATES. 
Fig. 2. From above, about 3 diam.; the allantois nearly 
covers the embryo.’ 7, vena afferens; 7, vena termina- 
lis; laid June 23, opened July 18, 1855. 
Fig. 2a. From above, about 5 diam.; laid June 23, opened 
July 17, 1855. 
Fig. 8. From below, about 5 diam.; laid June 18, opened 
July 25, 1855. 
Fig. 4. From the right side, about 5 diam. 0, allantoidian 
artery ; ¢, allantoidian vein running along the side of the 
Taken from the oviduct June 20, 
and opened July 18, 1855. 
abdominal opening. 
Fig. 5. From above, about 24 diam.; laid June 18, opened 
July 17, 1855. 
Fig. 6. From above, about 1} diam.; laid June 18, opened 
July 10, 1855. 
Fig. 7. From above, about 1} diam. ; laid June 23, opened 
July 10, 1855. 
Fig. 8. 
oviduct, June 20, and opened July 10, 1855. 
Fig. 9. From above, about 1} diam.; laid June 18, opened 
July 10, 1855. 
Fig. 10. 
oviduct, June 20, and opened July 10, 1835. 
From above, about 1} diam.; taken from the 
From above, about 14 diam.; taken from the 
Fig. 11. From above, about 2 diam.; laid June 18, opened 
July 11, 1855. 
Fig, 12. From above, about 2 diam.; period of laying un- 
known, opened June 25, 1854. 
Fig. 13. From above, nat. size; laid June 12, opened Sep- 
tember 1, 1855. 
PLATE XV. 
{Drawn from nature, by A. Sonrel.] 
All the figures are of Chelydra serpentina. 
Fig. 1. 
being taken off; fig. 3, the allantois and amnios cut away ; 
From the right; fig. 2, from the left side, the shell 
nat. size; fig. 1 and 2, laid June 10, opened Sept. 20, 
1855; fig. 3, laid June 10, opened Sept. 21, 1855. 
Fig. 4, 5, 6. 
the allantois cut away, leaving the inner folds with their 
From above, nat. size; fig. 4, outer folds of 
bloodvessels running over the amnios; fig. 5, to the right 
the whole allantois is lifted off and cut away so as to 
expose the radiating vessels of the vascular area; laid 
June 18, opened Sept. 6, 1855; fig. 6, the allantois en- 
tire; taken from the oviduct June 20, opened Sept. 4, 
. 1855; fig. 5a, a portion of the large vena afferens of fig. 
5, and the two omphalo-meseraie arteries at the point 
where they begin to branch, about 5 diam. 
Fig. 7. 
away ; laid June 21, opened Sept. 21, 1855. 
From the right side, the allantois and amnios cut 


