590 DR. J. E. GRAY ON A NEW WHALE. [Nov. 22, 
B. The atlas separate, free; the other cervical vertebre united into 
a single mass by the coalescing of the body and neural arches. 
a. The atlas with a large, high keel over the neural arch. 
Macleayius. 
b. The atlas with a very slightly elevated keel over the neural 
arch. Catodon. 
The fact of the atlas being free and separate, as in the Sperm 
Whales, makes it possible that this genus may be a Toothed Whale 
allied to the Sperm Whales. But the form of the neural arch, and 
especially of the lateral processes, induces me to believe that it is 
most probably a Whalebone Whale allied to Balena, and probably 
belonging to the family Balenide. 
Axis of Catodon australis. 
In that case the most natural way of arranging the genera which 
have the cervical vertebrze united into one or two masses will be as 
follows :— 
A. The neural arch with a strong well-developed ridge on its upper 
edge, forming a keeled crest. 
a. The lateral processes of the atlas on the upper part of the side. 
Balenide. 
* The atlas-vertebra united with the other cervical vertebre intoé a 
single body. Baleena. LEubalena. 
** The atlas-vertebra free from, and separate from, the other 
cervical vertebra. Macleayius. 
b. The lateral process of the atlas and other cervical vertebre on the 
lower part of the side of the body. Uyperodon and Lagenocetus. 
