318 Dr. J. E. Gray on the Whalebone-Whales, 



edge, on each side of the palate. The tympanic bones are largo, 

 conch-like, attached to the expanded periotic bones, which are 

 articulated to the skull. The lachrymal and malar bones are 

 small and thin, and are often lost in preparing the skulls. 



The Whalebone-Whales may be divided into two families, 

 thus : — 



Fam. 1. Balaenidse. (The Right Whales.) 



The belly smooth, without any longitudinal folds. Dorsal fin 

 none ; pectoral fin broad, truncated at the end. Maxillary bones 

 narrow. Baleen elongate, slender, straight. Tympanic bones 

 rhombic. Scapula higher than wide. 



A. Head very large j of adult, two-fifths the entire length. Baleen elongate, 



slender, with' a single series of very fine elongate central fibres, forming 

 afine flaccid fringe. Enamel thick, polished. 



1. Bal^na. 



Bibs 13 ; the first like the others, single-headed ; the tympanic 

 bone rhombic, aperture oblong, only slightly contracted at the 

 upper end, and about two-thirds the length of the bone. (Proc. 

 Zool. Soc. 1864, p. 201, f. 1.) 



1. Balaena mysticetus, Cuvier, Oss. Foss. v. t. 25. f. 9, 10 (adult). 

 (Greenland Right Whale.) 



Bal(ena mysticetus arctica, Schlegel, Abh. 36. 

 Nordhval, Eschr. 



Hab. Northern Sea, Greenland. 



2. Balana Biscay ensis, Eschr. & Van Ben. 



Hab. The Bay of Biscay. I have seen no remains of this 

 Whale. 



8. Balcma marginata, Gray, Zool. Ereb. & Ter. 48, 61. f. 1. 



Only known from some plates of baleen received from 

 Western Australia. This is undoubtedly a very distinct species. 

 The baleen is of nearly the same structure as that of the Green- 

 land Whale; but we do not know what may be the form of the 

 first ribs or of the bones of the other parts of the skeleton. 



B. Head large; of adult, about one-fourth the entire length. Baleen elongate, 



broad at the base, with several series of rigid central fibres, forming a 

 rigid fringe. Enamel thin, 



2, EuBAL^NA, Gray, Proc. Zool. Soc. 1864. 

 Ribs 15 ; the first like the others, single-headed. Tympanic 



