Dr. J. E. Gray on the IV halebone-W hales. 345 



wards the hinder angles, the latter armed with a broad, flattened, 

 slightly curved, oblique spine, its upper surface thickened, its 

 apex directed backwards; the narrow lateral border, together 

 with the apical margin, serrate ; humeral callus obliquely ele- 

 vated, its apex acute; each elytron with three strongly raised 

 costje, the first still more strongly elevated at the base, the se- 

 cond and third both commencing at the apex of the humeral 

 callus, the outer one serrate; interspaces deeply bigemellate- 

 punctatc ; the two oblique vitta; extend from the lateral margin 

 nearly to the suture, the first running along the hinder edge 

 of the raised humeral callus, the second being placed just below 

 the middle of the disk. 

 In my own collection. 



[To be contdnued.] 



XXXVIIl. — Notes on the IVhalehone-Whales ; with a Synopsis 

 of the Species. By Dr. John £dward Gray, F.R.S. &c. 



The rarity of their occurrence, the difficulty of naturalists ex- 

 amining them when they do occur, and especially of comparing 

 them with other specimens, explain why the Whalebone-Whales 

 have been so imperfectly known ; and, when observed, the spe- 

 cimens are so large that it is almost impossible for the eye of 

 the naturalist to take them in as a whole, and to compare the 

 parts in detail. 



The allied species are so alike externally, that naturalists and 

 others who have had the opportunity of examining them have 

 been inclined to regard the different specimens observed as only 

 states of growth of the same species ; and, for the same reason, 

 the specimens which have been observed in different parts of 

 the world have been regarded as alike ; and thus the belief has 

 become general that the species of Whalebone-Whales have a 

 very extended geographical distribution. 



The examination and comparison of the few skeletons that 

 have been collected have shown that there are many more spe- 

 cies than has been generally supposed, and seem to lead to the 

 conclusion that each species of Whalebone- Whale has only a 

 comparatively limited geographical range ; and the observation 

 of whales seems to make it probable that some of them make 

 periodical migrations within these limits. 



The study of the subject, and especially of the bones that 

 have been collected, has led me to the following conclu- 

 sions : — 



1. That, though the adult Whalebone-Whales have a large 

 head compared with the size of the body, the head of the foetal 



