132 



ZOOLOGICAL SOCIETY. 



Feb. 28, 1865.— Dr. J. E. Gray, F.R.S., iu the Chair. 



Description of a new Species of Porpoise in the Museum 

 OF Buenos Ayres. By Dr. H. Burmeister, F.M.Z.S. 



Phoc^na spinipinnis, sp. nov. 



The animal has the general figure of the common European spe- 

 cies, but differs entirely in the position of the dorsal fin, which is 

 placed further backwards, and has spines on the upper edge. 



The whole body is black, without any other colour, and the sur- 

 face of the skin is transversely striated with fine excavated lines, like 

 the inside of the human hand. The upper lip is somewhat shorter 

 than the under, and the figure of the mouth, on both sides, rather 

 curved behind ; the length of the opening is 8^ centim. on each 

 side. From the hinder corner of the mouth the eye is distant 

 7 centim., and from the eye to the beginning of the pectoral fin is 

 1 6 centim. The opening of the nose has the form of a broad trans- 

 verse ridge, somewhat curved forwards; it is 3 centim. broad, and 

 16 centim. distant from the top of the upper lip. The figure of the 

 whole body is fusiform, but much more elongated behind than be- 

 fore ; it measures from the top of the upper lip to the notch of the 

 tail-fin 162 centim., and the circumference of the thickest part of the 

 body, at the middle, is 102 centim. 



Fig. 1. 



Fig. 2. 



The distance from the nasal aperture to the beginning of the dor- 

 sal fin is 84 centim. ; but the elevation of this fin is so gradual, that 

 it is difficult to say exactly where it begins. The figure of the whole 

 fin is triangular, somewhat curved forwards near the end, and its 

 height 14 centim. (see fig. 1). This curving forwards is a peculiar 

 and very distinguishing character of the species, as is also the 

 clothing of the anterior margin of the fin with small spines. These 

 spines are not diff'erent from the skin, but elevations of the skin itself, 

 like small angles, of an elongated-oval form. I have figured part of 

 the middle (where the spines are most elevated) as seen from above 

 (see fig. 2), to show that every spine is surrounded by a ridge of the 

 skin, and that from the sides of the lateral spines other ridges begin. 

 Some small spines begin in the middle of the back, at the distance 



