Dr. J. E. Gray on the Arrangement of the Cetaceans. 171 
If the arrangement of the species into genera requires mature deli- 
beration and the study of the value of the different characters ob- 
served as to their permanence and variability in each group (and the 
variations in different organs are often of very different value in this 
respect in very nearly allied groups), then the arrangement of the 
minor groups into larger and larger ones, according to my experi- 
ence, and indeed as any one may @ priori suppose, demands a greater 
power of comparison and reasoning, since there are a greater number 
of facts, of characters, and of resemblances or differences, and of varia- 
tion or permanence, to be considered and reasoned on—that is to say, if 
the constituents of the larger groups are conscientiously examined 
and determined on, as they must be to render them of value for the 
purposes above stated. 
I am aware that this is not the feeling of many zoologists, but I 
believe this arises from most zoologists restraining themselves to the 
study of a limited number of species or genera. This is proved by 
the fact that many zoologists pay great attention as to who was the 
first person who gave the name to a genus, though the genus may 
have been restricted, or even extended, and its characters completely 
altered since the name was first applied, but pay little or no atten- 
tion to the first person who formed a group, or to the synonymy or 
history of the changes which have taken place in the characters or 
arrangement of the group or genera themselves. This is not the 
ease with botanists, who are generally much better grounded in the 
philosophy of science. They are careful in giving the synonyms of 
the families and subfamilies, as may be seen in the works of DeCan- 
dolle and others. And it is very desirable that the same attention 
should be paid to the subject in zoological essays. 
The order Cetacea must be divided into two suborders, viz. CeTE 
and Srrenra. I have nothing to add to the arrangement of the 
second suborder. 
Suborder I. Crere. 
Skin smooth, bald. Teats two, inguinal. Limbs clawless; the 
fore limbs fin-shaped; hinder united, forming a forked horizontal 
tail. Nostrils enlarged into blowers. Carnivorous. 
I. The nostrils longitudinal, parallel or diverging, covered with a 
valve, one often larger and more developed. 
Fam. 1. BALZNID&. 
Head very large, depressed. Nostrils separate, nuchal. Teeth 
not developed in the adult. Palate furnished with transverse horny 
fringed plates of baleen or whalebone. 
a. Dorsal fin none ; belly smooth ; baleen elongate, slender ; vertebre 
of neck united ; pectoral broad, truncate at end. 
1. Bata@na. Pectoral fin moderate. Head one-third of the entire 
length. 
