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. 10. The same, inner view of mandible, x 43 diam. 
. 11. The same object, outer view, x 43 diam. 
PROF, W..K. PARKER ON THE ‘STRUCTURE AND 
PLATE LXIV. 
. Alligator mississipensis (2nd Stage). Subhorizontal section of head (No. 1), 
lowest, x 10 diam. 
. The same (No. 11), X 10 diam. 
. The same (No. 111), X 10 diam. 
. The same (No. iv), highest, x 10 diam. 
. Crocodilus palustris (3rd Stage): embryo, 2 inches long. Base of skull, upper 
view, X 63% diam, 
Part of same object, x 20 diam. 
. Crocodilus palustris (5rd Stage): 23 inches long. Palatal view of head, 
xX 43 diam. 
The same object,.dissected, X 43 diam. 
The same, upper view of head, dissected, X 43 diam. 
PLATE LXV. 
. Crocodilus palustris (4th Stage): embryo, 3} inches long. Chondrocranium 
of embryo, upper view, X 53 diam. 
. The same object, lower view, X 53 diam. 
. Part of same object, outspread, lower view, x 8 diam. 
. Same embryo, visceral arches, obliquely external view, x 53 diam. 
. Alligator mississipensis (5th.Stage): larger embryos of this species, 4} inches 
long. Palatal view of head, with lower arches removed, X 3 diam. 
. The same, head in vertical section, x 43 diam. 
. The same object, with the brain removed, x 43 diam. 
. The same head, outer view of chondrocranium, X 43 diam. 
. The same head, upper view of hyobranchial plate, x 43 diam. 
PLATE LXVI. 
. Alligator mississipensis (5th Stage): largest embryos. Dissected skull, side 
view, X 44 diam. - 
. The same, inner view of mandible, x 4} diam. 
. The same, lower view of-skull, x 44 diam. 
. The same, upper view of skull, x 43 diam. 
. The same, transversely vertical section (1st) of head through external nostrils, 
x 8 diam, 
