34 
ZOOLOGICAL LITERATURE. 
they have the usual form of these bones in the Balcenopterida ; 
and though the entire lateral process becomes ossified in Physalus 
and SMaldius, the end of the process remains cartilaginous at 
least to a much greater age, if not always, in the genera Mega- 
pten'a and Benedenia. Therefore this apparently imperfect de- 
velopment and truncated form of the hones is a peculiarity of 
the genera, and does not arise from the youth of the specimens 
observed. Further, the fact that some species have the fii’st rib 
furnished with a double head, one head attached to the last 
cervical, and the other to the first dorsal vertebra, though con- 
sidered by Schlegel as only to be found in the young state of 
the species, disappearing as the animal increases in age, proves 
to be a permanent peeuliarity of considerable importance. 
The arrangement is nearly the same as that proposed in the 
preceding paper, with the following additions : 
Iluntm’us (p. 349) is a fourth genus of Farn. 1. Balamidce, and distinguished 
from the three others in having fifteen ribs, the first double-headed ; tympanic 
bones rhombic, nearly like those of Balcena ; head large, forming above one- 
fourth of the entire length of the adult. The typical species is Balmia mys- 
ticelus australis (Schleg.) or Ilunterus temminckii (Gray). — The Whalebone- 
Whale of the North Pacific, figured in the ^ Fauna Japonica ' under the 
name of Balcena australis^ but afterwards named by Dr. Gray B. japmica^ 
must receive another name, the latter being preoccupied. He now proposes 
to call it Balcena sieboldii j its position in the system is still unknown, no 
remains of it having been sent to Europe. 
The genus Poescopia is again divided j and the characters of the genera of 
Megapterina would be as follows : 
a. Blade-bone without any acrdmion 6r coracoid process j the bodies of the 
cervical vertebrae subcircular ; arm-bones broad ; Meyuptera {Balc&na longi- 
mana, Bud.). 
h. Blade-bone with a small 6ora6oid process ; the bbdies of the cervical 
vertebrae nearly square, with the angles rounded : Pascopia {Balcena la- 
landiiy Fisch.), 
c. Blade-bone with a distinct acromion and coracoid process \ arm-bones 
more slender ; fingers — ? : EschrichUus (p. 350), with the species Bcdcenoptera 
rohusta (Lilljeb.) and Megaptera novce zelandicB (Gray). 
^ Subsequently, Proc. Zool. Soc. 1864, p. 587, Dr. Gray received 
the photographs of the cervical vertebrae of a Bight Whale, pre- 
served in the Museum of Sydney ; he has recognized in these 
remains a new generic form, for which he proposes the name of 
Macleayius australiensis. He says that the genera of large 
Whales may always be recognized from the cervical vertebrae, 
and arranged according to this character thus : 
I. The neural arch with a Strong, weil-dCveloped ridge on its upper edge, 
forining a keeled crest. 
A. The lateral processes of the atlas on the upper part of the side. Ba- 
Icemdce, 
