THE GENETIC RELATIONS OF THE CETACEANS. 27 
characters, and the rest of the organization is not in disaccord 
with those evidences of generalization. 
On the whole, it appears to me that the long-necked Cetaceans 
represented by the living Iniids and Platanistids and in greater 
number by various forms in the Tertiary epoch are best entitled to 
the first rank. Whether of those, the Iniids or the Platanistids 
are the first is equally unctrtain, but as the latter are certainly in 
some respects the most specialized, to the Iniids may be conceded 
. the rank provisionally. 
Probably, as more differentiated offshoots from the same secon- 
dary stem as the Iniids and the Platanistids, may be considered 
the Delphinids, of which the Pontoporiinz doubtless ee the 
most generalized form. 
Recommencing with the other secondary stem, apparently the 
Ziphiids represent the oldest rank, and the Physeterids are the re- 
sults of an offshoot from the same lineage. 
I have thus endeavored to present my views, and I trust that 
the language I have employed may prevent me from being mis- 
understood to mean that any one of the known specialized forms 
is derived from another of the known specialized forms. I have 
simply essayed to indicate what now appear to me to be the prox- 
imate relations of the several forms, and respectively the more 
generalized of the approximated groups. The following table may 
more vividly convey my views; in each case, the left branch indi- 
cates the supposed most generalized and the quasi-oldest form: 
(Eocetus) 
è 
| ZEUGLODONTIA. | MYSTICETE. | DENTICETE. 
2 er 
£ $ 
5 S 
3 ae cae a 
e el ee 
S 8 z - = N N 
. i=] E. o e 
F EA E = > -i 
= 8 Lang ~ hy Ei = a 
a si z ~ i 3 a 
= oe = g a a 
= B E = 
8 ? B E E F 
g pa 8 E 
ao S S ! 
3 ri 
u 0 
s- 
& ao 
8 z= 
7 B 
= 
= 
