EXPLANATION 
June 21, opened July 31, 1855; fig. 2a, a lung from fig. 
2, 40 diam. 
Fig. 3. Lungs and windpipe, from below, slightly magni- 
fied; fig. 3a, the same as fig. 3, one lung is turned so as 
to show the broad side, 40 diam.; laid June 23, opened 
July 30, 1855. 
Fig. 4. Left lung and the windpipe, in profile, 25 diam. ; 
laid June 12, opened July 29, 1855. 
Fig. 5. Left lung, the side next to the esophagus, 25 diam. ; 
laid June 23, opened Aug. 7, 1855. 
Fig. 6. Part of a trachea close to the lung, 40 diam.; pe- 
riod of laying unknown, opened Sept. 2, 1852. 
Fig. 7. Left side of the head and shoulders, 25 diam.; pe- 
riod of laying unknown, opened July 30, 1852; fig. 7a, 
head of fig. 7, seen from the end. 
Fig. 8. The right eye, 40 diam.; laid June 22, opened 
July 22, 1852. 
Fig. 9 and 9a, 25 diam.; period of laying unknown, opened 
Aug. 7, 1852. Fig. 9a, head, heart, and shoulders from 
below; fig. 9, region of the heart of fig. 9a, the right side. 
(In this figure, # should be j*, and j? should be #.) 
Fig. 10, 10a, 10b. The heart, 5 diam.; fig. 10, the ventral 
face ; fig. 10a, the dorsal face ; fig. 10b, the ventral face, 
the ventricle (4*) cut open. In all three figures, h', 1, 
indicates the pulmonary arteries; h*, 1°, the auricles; h', 
the ventricle ; pa, the left aorta; the double vessel with- 
out letters is the right aorta; vo, valvular opening be- 
tween the auricles and ventricle; vl, valves of vo; laid 
June 18, opened Sept. 3, 1855. 
Fig. 11. 
laid June 21, opened Aug. 8, 1855. 
Fig. 12. The head of fig. 9a cut off and seen from behind, 
about 5 diam. 
Fig. 13. Posterior end of Pl. 12, fig. 1, from above, 250 
diam. ; fig. 13a, surface of fig. 13. 
Fig. 14. Posterior end of the left side of the body, 25 diam., 
seen on dark ground; laid July 14, opened Aug. 25, 
1852. 
Fig. 15. Posterior end of the left side of the body, 8 diam. ; 
period of laying unknown, opened July 31, 1852. 
The head, from below to show the mouth, 3 diam.; 
PLATE XXV. 
[Fig. 2, 8, 9, 10, from nature, by A. Sonrel; all the others by 
H. J. Clark.] 
Fig. 9, Cistudo virginea; fig. 10, 11, Chrysemys picta ; fig. 
12, Ozotheca odorata; the others, Chelydra serpentina. 
Fig. 1, 1a, 8, 3a, 9, 10, are lettered in the same manner: bk, 
OF THE PLATES. 



La 
639 
beak; h, heart; A! aorta; n', intestine ; n®, stomach; n‘, 
cesophagus ; n°, anus; n°, urinary bladder, or in fig. 3, 
allantois; n’, remains of the neck of the yolk sac, or in 
fig. 8 and 8a, the whole yolk sac; oh, hyoid bone; 4, 
Wolffian bodies; 7, liver; t, windpipe; ?/, lungs; v, nos- 
trils ; x, lower jaw in fig. 1a, opening of the mouth in fig. 
9 and 10. 
Fig. 1. 
diam.; period of laying unknown, opened Aug. 30, 
1851. 
junction of the cesophagus and intestine, cut open, seen 
Intestines, heart, and liver, seen from below, 24 
Fig. 1a, intestine stretched out, nat. size; fig. 1b, 
from within, 5 diam.; fig. 1c, piece of the long intes- 
tine laid open, 5 diam.; fig. 1d, piece of the thick in- 
testine laid open, 5 diam. 
Fig. 2. 
Fig. 3. 
3a, cut open from above; the yolk sac (n’) has lost part 
See below, after fig. 3 and 3a. 
Cut open from below, nat. size, just hatched ; fig. 
of its contents, and shrunk; the dotted line indicates 
its outlines when uninjured. 
Fig. 2, 4, 5, 6, 6a, 7, 7a, are lettered in the same manner: a, 
the Wolffian bodies; a’ in fig. 6b is the same as d; b, kid- 
neys; 0/, posterior, and !! anterior end of 6; c, duct of 
Wolffian body; e!’, posterior opening of c; d, abdominal 
veins, see also a! above, in fig. 6b; e, ureters of the kid- 
neys; f, vas deferens of the testicle (n) ; g, anal pouches ; 
g', aperture of g; , dorsal or abdominal artery, or in fig. 
2, the heart; 4’, arteries going to the hind legs; in fig. 2, 
it is the aorta; 7, vena afferens; in fig. 6 and 7, it is put 
by mistake for the vessels which go to the Malpighian 
corpuscles; j*, j*, forks of the omphalo-meseraic artery ; 
k, intestine ; /, cloaca ; m, anus; m’, opening of the intes- 
tine into the cloaca; n, genital organ; n/, anterior pro- 
longation of n; 0, allantois; r, liver; w, gall cyst. 
Fig. 2. 
from the right side, 6 diam.; laid June 18, opened Sept. 
4, 1855. 
Fig. 4. Left Wolffian body in profile, 6 diam.; laid June 
12, opened Aug. 13, 1855. 
Fig. 5. Piece of the left Wolffian body and kidney, 12 
diam.; period of laying unknown, opened Aug. 31, 1852. 
Fig. 6. 
fig. 6a, the same as fig. 6, from below; fig. 6b, transverse 
Heart, liver, Wolffian bodies, and kidneys, seen 
Wolffian bodies and kidneys, from above, 6 diam.; 
section of fig. 6, and 6a; laid June 12, opened Aug. 29, 
1855. 
Fig. 7. Left Wolffian body and kidney, from below, 5 
diam.; fig. 7a, upper side of fig. 7, the upper end is the 
anterior. Just hatched. 
Fig. 8. An embryo deprived of its envelopes, 2 diam.; the 
same as Pl. 15, fig. 4, 5, 5a, 6. 
Fig. 9. Head of Pl. 18, fig. 10d, 3} diam. 
