Dr. J. HE. Gray on the Whalebone-Whales. 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 
coste, 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; imterspaces deeply bigemellate- 
punctate; the two oblique vitte 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 continued. ] 
XXXVIIT.—Notes on the Whalebone-Whales ; with a Synopsis 
of the Species. By Dr. Joun Epwarp Gray, F.R.S. &c. 
Tue rarity of their occurrence, the difficulty of naturalists ex- 
amining thera 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- 
slons :— 
1. That, though the adult Whalebone-Whales have a large 
head compared with the size of the body, the head of the foetal 
