1865.] DR. J. E. GRAY ON A NEW BRITISH PORDOISE. 319 
The Zoological Society, who are so anxious to obtain specimens 
of these animals that their habits may be studied, procured with 
considerable trouble a fine male Porpoise, which had been caught at 
Margate. It was carried to the Gardens, and placed in the pond 
formed for these animals; but, though showing no external injury, 
it was in so weak a state when it arrived that it sank to the bottom, 
and was obliged to be taken out and suspended by bands on the sur- 
face of the water so that it might not be choked. After a time it 
recovered so as to be able to swim about by its own exertion, but it 
only survived the transport a few days. 
Messrs. Bartlett and Gerrard, when it was alive, said that it dif- 
fered so much in general appearance from the Common Porpoise that 
they were induced to believe that it might be a species of Lageno- 
rhynchus or Grampus. ; 
The general form of the head, and examination of the teeth after 
death, proved at once that it was a species of Phocena, very nearly 
allied to, if not identical with, Phocena communis. 
Dr. Burmeister’s description of a Phocena from the River La 
Plata (contained in the Museum at Buenos Ayres), which is peculiar 
for having some spines on the upper edge of the dorsal fin, naturally 
made me careful in examining the edge of the fin of this specimen; 
and to my astonishment I discovered that this species also was pro- 
vided with a series of compressed tubercles, giving the fin a sharp, 
hard, serrated appearance. 
The tubercles or spines on the dorsal fin having been observed in 
two specimens from very different localities, I was induced to inquire 
if it was a character common to the genus, which had been over- 
looked; but, on examining the stuffed specimen of the Common 
English Porpoise in the Museum, it is clear that they are not found 
in the common state of the species. It then occurred to me that 
it might be a peculiarity of the male sex; but Mr. Flower informs 
me that the male specimen which lived for some weeks in the Gar- 
dens of the Society, and which he lately dissected, certainly had no 
spines on the edge of the dorsal fin; so that cannot be the case. 
Under these circumstances I think I am justified in considering 
that the existence of these spinous tubercles is a peculiarity of the 
species, and probably a specific character. The examination of the 
skull shows that there are differences in its form which confirm 
this opinion. 
The species of Phocena may be thus defined :— 
a. Back in front of the dorsal fin, and upper edge of the dorsal jin, 
smooth, without tubercles or spines. Dorsal jin on the middle 
of the back. 
1. PHocz#zna communis. 
Hab. North Sea and mouths of rivers. 
b. Back in front of the dorsal fin smooth; the upper edge of the 
dorsal fin with a single series of oblong compressed tubercles, 
