632 
Fig. 10. From the right side; fig. 10a, from above; fig. 
10b, from below ; fig. 10c, from the left side, the allantois 
partly opened ; fig. 10d, the same, the allantois being cut 
away ; fig. 10e, the same, from behind ; fig. 10f, the same 
as 10d, 10e, from above. Cistudo virginea, nat. size. 
Just ready to hatch. Period of laying unknown; fig. 
10, 10b, 10c, opened Aug. 31, 1855 ; fig. 10a, 10d, 10e, 
10f, opened Sept. 5, 1855. 
Fig. 11, 11a, 11b, a, >. Crystals of nitrate of lime. 
508, on the structure of the egg-shell. 
See p. 
PLATE XVIIIa. 
[Fig. 1, 2, 8, from nature, by A. Sonrel, the others by H. J. Clark.] 
Fig. 11, 12, 13, 14. Nanemys guttata, the others, Chelydra 
serpentina. Throughout the Plate the letter a designates 
the amnios; a', the cephalic hood; a’, the caudal hood; 
e', the medulla oblongata; e°, the corpora quadrigemina ; 
e*, the choroid plexus; f, the vertebrae; i, the heart; x’, 
the aorta, or aortic bulb; h?, the branchial aorta; 4°; the 
auricle; h*, the ventricle; i, the vena afferens; 7, the 
allantoidian vein; 2°, the abdominal vein; 7, the junc- 
tion of the allantoidian and abdominal vein; *, the 
cephalic vein; j, the cephalic artery ; 7°, the dorsal 
artery ; j°, the allantoidian artery ; j*, the omphalo-mes- 
eraic artery; /°, the junction of the abdominal or dorsal 
artery and the omphalo-meseraie artery ; 7°, the june- 
tion of the abdominal and allantoidian arteries; k, the 
eyes; /, the ears; m, the branchial fissures; n/, n', the 
intestine ; n’, the stomach; n°, the junction of the allan- 
tois and intestine, except in fig. 5, where it refers to the 
cesophagus; n*, the wsophagus; n°, the anus; q, the 
Wolffian bodies; r, the liver; ¢, the windpipe; ¢, the 
lungs; u, the gall cyst; v, the nostrils. 
Fig. 1. Head of Pl. 15, fig. 7,4 diam. ; j', cephalic arteries. 
Fig. 2. Young turtle from above, 2} diam. Taken from 
the oviduct, July 20, opened Sept. 19, 1855. 
Fig. 3. From below, 2 diam. Laid open to expose the 
organs ; the same as fig. 2. 
Fig. 4. Wolflian body, intestine, liver, and bloodvessel dis- 
sected out; the anterior end is on the right; about 5 
diam. Laid June 12, opened July 29, 1855. 
Fig. 5. 
anterior end is to the left; the same as fig. 4. 
Fig. 6. 
June 18, opened July 25, 1855. 
Fig. 7. Anterior end of fig. 8, from above; fig. 7a, posterior 
Where the 
Heart, vessels, liver, intestine, dissected out; the 
Heart and branchial aortx, about 10 diam. Laid 
end of fig. 8, and 9, from below, laid open. 

EXPLANATION OF THE PLATES: 
allantoidian arteries (/*) join the abdominal artery, (j*,) 
the intestine (n') is cut away. 
Fig. 8. This figure, the largest of the Plate, is erroneously 
marked 2 in most copies. The same as fig. 6, 7, 7a, 9, from 
The Wolflian body (qg) is drawn down a 
little, to expose the dorsal artery (j*); about 10 diam. 
the right side. 
Fig. 9. The same as fig. 8, from below, about 5 diam. Laid 
open before and behind, and the allantois, the amnios, 
and the yolk sae turned aside. 
Fig. 10. Heart, and adjoining vessels, dissected out; 10 
diam. Laid June 13, opened July 17, 1855. 
Fig. 11. Heart, and branchial arteries from the right side ; 
25 diam. Laid July 14, opened Aug. 2, 1852. 
Fig. 12. 
Fig. 13. Anterior part of the body from the right side, 12 
diam. Laid July 15, opened July 26, 1852. The dotted 
lines which should connect the letters 1? and i’ are un- 
Heart, from the left side ; the same as fig. 11. 
fortunately omitted ; /* should go to the dark hole in the 
heart, which is nearest to the letter, and 4‘ to that part 
of the aorta which is just below the longest branchial 
fissure, (m,) that runs from the ear (b) downwards. The 
i nearest to the letter 4° should be 7. 
Fig. 14. From the left side. The amnios, (a,) behind the 
head, laid open; 12 diam. Laid July 10, opened July 20, 
1852. The first letter to the left of k should be e* in- 
stead of e'. 
PLATE XIX. 
[Drawn from nature, by H. J. Clark.] 
Fig. 1, 2, 3,4, 5 to 5d, 6, 7, 8, 22 are from Nanemys gut- 
tata, the others from Chelydra serpentina. 
Fig. 1. Cells on the surface of the head near the eye, 300 
diam. Laid July 18, opened July 28, 1852. 
Fig. 2. 
cell; b, its mesoblast. Laid July 11, opened July 22, 
1852. 
Fig. 3. A vertebra, 500 diam. Laid July 18, opened July 
27, 1852. 
Fig. 4. 
body, and between the vertebrae, 40 diam.; (a, cells from 
the dermal layer, (/,) 500 diam.) ; a’, spinal tube; 6, 
chorda dorsalis ; ec, dorsal artery; d, Wolffian bodies ; 
Surface cells of the tail, 500 diam.; c, profile; a, a 
Transverse section across the middle region of the 
e, duct of d; f, musculo-cutaneous layer; g, mesenterium 
About 18 days old. 
Surface view of the anterior end of the chorda dor- 
of the intestine. 
Fig. 5. 
salis; a, cell in profile; fig. 5a, surface view near the 
posterior end ; a, cell in profile; fig. 5b, middle region ; 
a, view of the surface; 4, of the interior; 500 diam.; fig. 

