Botany and Zoology. 127 
wards, because, like the vertebree of the tail, they lose their typical 
character as they recede from the common centre or trunk. - 
eral results of the Professor’s analysis may be thrown into the follow- 
ing tabular form :-— 
Primary Segments of the Skull-bones of the Endo-skeleton, 
VERTEBRE. OCCIPITAL. PARIETAL. FRONTAL. NASAL. 
‘en Basioccipital. |Basisphenoid, |Presphenoid. _|Vomer. 
Neurapophyses. Exoccipital. Alisphenoid. | Orbitosphenoid.|Prefrontals. 
Wastin pines. Supraoccipital. |Parietal. Frontal. Nasal. 
Parapophyses, Paroccipital. Mastoid. Postfrontal. None, 
Pleurapophyses. Scapula Stylohyal. . |/Tympanic. Palatal. 
Hemapophyses. Coracoid. Ceratohyal. Articular. Maxillary. 
Hemal Spines. Episternum, Basihyal. Dentary. Premaxillary. 
Diverging appendage.\Fore-limb or fin. |Branchiostegals.|Operculum. Pterygoids &Zygoma. 
cephalon, or olfactory crura and ganglions. : 
The superior development of the cerebral hemispheres in the warm- 
blooded class, and their enormous expansion in m, occasions cor- 
responding development of the neural spines, not only of their proper 
t 
tebree, but the organ itself is intercalated between t ural arches 
of these segments and its ossified capsule; the petrosal projects into 
sphenoid and orbitosphenoid; but the gustatory organ is far removed 
from the neural arches or cranium proper, 
ve 4 
: the vertebral elements are 
modified to form cavities for these organs of sense ; that lodging the 
eye being called the “ orbit,” that for the ear the ** otocrane. 
The divergence of the olfactory crura, and the absence of any union 
leads to an extension of 
? 
Ives coalesce together there in batrachia, 
birds, and mammais. This extreme modification was to be expected 
