108 



BAL^NOl'TERID.!!:. 



changes which may take place in the development of the bones 

 during growth and the variations that may occur in individuals of 

 the same species, show that the species of Finner Whales which 

 inhabit the northern hemisphere are niiich more numerous than was 

 formerly suspected ; and it is probably the same with those that 

 inhabit the southern half of the globe. 



Professor Eschricht, in 1846, had so little confidence in the number 

 of species of Whales inhabiting the North Sea, that he considered 

 that he had made an advance when he thought it was proved that 

 there were at least three different species having their abode in the 

 North Sea (4th Mem. p. 157). 



Cuvier, in his essay in the ' Ossemens Fossiles,' admits three kinds 

 of Finner ; each of them now forms the type of a genus : llorqual du 

 Cdi'^=^Megaptera ; Eorqual de la Meditcrranee = P%AYf?«s; Eorqual 

 du 'NoTd=SibhaIdius and Balcenoptera. Van Beneden, in 1861, 

 progresses one step fiu'ther ; he admits four — that is, separates the 

 Rorqual du Nord into two species : thus, — 1. Pterobahena minor= 

 Balcenoptera ; 2. Pterohalcena commimis^^Plujsalus (and perhaps 

 Benedenia); 3. P. c/igas=Slbbal(Uus; 4. Kypliobcdcma longhnana = 

 Megaptera. (See Nouv. Mem. Acad. Hoy. Brus. 1861, xxxii. 38.) 



The whalers recognize three kinds: — 1. The Humpback {Mega- 

 pterina) ; 2. The Finner (Phi/salina) ; 3. The Beaked Whales 

 (Bidcenopterina), considered in this Catalogue as tribes. 



" Sometimes chase is given to the Finback and the Humpback 

 Whales, but these are seldom caught, not only on account of their 

 superior cunning, greater wildness and celerity — by means of which 

 they are enabled to run out the longest line- — -but also because giving 

 less oil than the Black "WTiales they are not so frequently pursued." — 

 Dieffenbacli, Neiu Zealand, i. 42. 



It is possible, indeed not improbable, that the lateral processes of 

 the cervical vertebrje of all the Finner Whales are more or less ring- 

 like in the cartilaginous state, and that the different form of the 

 processes seen in the prepared skeletons may depend on the extent 

 to which the cartilage becomes ossified. If this is the case, the ex- 

 tent to which the cartilage does become ossified seems to be different 

 in the various species, and therefore offers a good character by which 

 to determine them. In some species the ring is entirely ossified, 

 while in others a large, and in others, again, only a small part of the 

 base of the lateral processes becomes bony. In species which have 

 a great part of the processes ossified, sometimes the two processes 

 unite into a ring on one side of the vertebra, and the processes keep 

 separate on the other. Yet, as far as I have been able to examine 

 the subject, the extent to which the processes become ossified seems 

 to be a good character of the species — of course liable to a certain 

 extent of variation, as all characters are. Some authors even seem 

 to believe that the lateral processes of the cei-vical vertebras are liable 

 to great variation in this respect during the age and decadence of 

 the animal. Yet the special form of the lateral bones which form 

 the more or less perfect rings, the comparative thickness of the upper 

 and lower processes with respect to each other, and their thickness 



