Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
3 
Fig. 3 
Fig. 4. The same, endocranium, upper view, x 6 diam. 
Fig. 5. The same, horizontal section of the nasal region of the skull, upper view, 
1 
2. 
DEVELOPMENT OF THE SRULL IN THE URODELES. 213 
PLATE XXXIX. 
. Stren lacertina: adult. The skull, side view, «4 diam. 
. The same: young specimen. The endocranium, upper view, X54 diam. 
1 
2 
3. The same: adult. The lower arches, upper view, <4 diam. 
4 
. Menopoma alleghaniensis: adult. The lower arches, left side, upper view, 
x 2 diam. 
. The same, auditory region of the skull, outer view, x4 diam. 
. The same, auditory region of the skull, oblique view, x2 diam. 
PLATE XL. 
. Lissotriton punctatus: larva, + inch long. The skull, upper view, x 24 diam. 
. Triton cristatus: larva, 24 inches long. The skull, upper view, x 7+ diam. 
. The same, lower view, X 74 diam. 
. Part of the same, upper view, x 142 diam. 
. The same largest larva, 2 in. 11 lines long, the lower arches, upper view, 
x 7# diam. 
. The same: a more advanced larva, with gills almost absorbed, 23 inches long. 
The skull, upper view, x7} diam. 
. The same, lower view, x 7+ diam. 
PLATE XLII. 
. Triton cristatus: adult. The skull, upper view, x6 diam. 
The same, lower view, x 6 diam. 
. The same, side view, 6 diam. 
a. The same, right mandible, inner view, x6 diam. 
<6 diam. 
Fig. 6. The same, suspensorium, lower view, X12 diam. 
Fig. 7. The same, the lower arches, upper view, x 6 diam. 
Fig. 7a. The same, thyrohyal of a younger specimen, upper view, X 6 diam. 
LIST OF ABBREVIATIONS. 
The Roman figures in the Plates indicate the nerves or nerve-foramina 
a.p. Ascending process. b.br. Basibranchial. 
ar. Articulars. b.hy. Basihyal. 
ar.c. Articular condyle. C’?. Cerebrum (fore and mid brain). 
a. s.¢c. Anterior semicircular canal. c.hy. Ceratohyal. 
a.tr. Apex of trabecula. c.st. Cephalostyle. 
au. Auditory capsule, 
