Dr, J. E. Gray on the Whalebone-Whales. 347 
the practical workingman and the trader being in advance of the 
scientific zoologist. 
5. The difference in form of the tympanic bones is great, and 
affords good characters, not only to separate the species from 
one another, but also to group them into families and genera. 
6. The fact that some Whalebone-Whales have the first rib 
furnished with a double head, one head attached to the last 
cervical and the other to the first dorsal vertebra, which had 
been observed by Rudolphi, Yarrell, Dubar, and Schlegel, 
though apparently considered as only to be found in the young 
state of the species by the latter author, disappearing as the 
animal increases in age, proves, I believe, to be a permanent 
peculiarity of considerable importance, and justifies Lilljeborg 
in using it as a character for the discrimination of the species, 
and even for separatmg the Whales into groups or genera. 
That it is not a peculiarity of the young state is proved by its 
being seen well developed in the skeleton of the gigantic Ostend 
Whale, which was formerly exhibited at Charing Cross and in 
other places. This peculiarity is found both in the Right Whales 
and in the Finners. 
Indeed, when the skeletons of the specimens from different 
localities can be examined, there are no want of characters to 
separate the Whales into genera and species—as, for example, 
the breadth of the upper jaw, the size and form of the ramus of 
the lower jaw, the form of the lateral processes of the cervical 
vertebree, the number of the dorsal and caudal vertebree, the 
form and size of the articulating surfaces of the vertebrae, the 
form and number of the ribs, the form of the os hyoides and of 
the sternum, the shape of the scapula and the development or 
non-development of the coracoid process, the form and propor- 
tions of the bones of the arm, and the number and comparative 
length of the bones of the paddle. I am convinced that, when 
more skeletons have been collected, the number of the species of 
these animals will be greatly increased, especially if the bones of 
the skeletons are kept separate, and not set up, so that the bones 
of the different species can be accurately compared. For it is to 
be observed, probably from the eye not being able to take in the 
peculiarities of so large a subject, that some of the best com- 
parative anatomists have regarded skeletons from very dif- 
ferent localities, as the Megaptere from the Northern Seas and 
from the Cape, as the same species, from a comparison of set-up 
skeletons, which were at once declared to be distinct when the 
separate bones were compared in detail. 
The Whalebone- Whales (Mysticete) are characterized by having 
only very rudimentary teeth, that never cut the gum, and by 
having cross rows of flexible horny plates, fringed on the inner 
