ON FOSSILS FROM NEW ZEALAND 165 
in the same collection, the humerus has a length of 4} inches, and 
a distal antero-posterior diameter of 24 inches; in other words, 
these diameters are as 21 to 1,—proportions which much more 
nearly approximate those of the fossil. But then the radial and 
ulnar facets are nearly equal: there is no distinct facet for the 
olecranon; and there is no anterior ridge. 
The nearest approximation to the fossil, which I have been able 
to meet with, is the humerus of the common Porpoise (Phocena 
conumunis) of our own seas. Its length is to the antero-posterior 
diameter of its distal end as about 2 to 1. It exhibits an anterior 
ridge, bounded by a groove on its inner side; its inner face has a 
slight elevation on the posterior half of its middle region; the 
radial facet is larger than the ulnar; and there is a distinct olecranar 
facet. But the plane of this facet is very little inclined to that of the 
rest of the ulna; the tuberous part of the anterior ridge occupies the 
lower third of the anterior face, and is separated by but a very small 
space from its distal end; and the anterior ridge above it is almost 
obsolete, so that the bone appears much constricted superiorly. 
While it presents certain resemblances to the humerus of Phocena 
therefore, the fossil bone differs widely from it, and still more from 
the same bone in any other genus of the Cefacea with which I have 
been able to compare it. I consider it therefore to indicate a distinct 
genus of Cetacea, which may be called Phocenopsis, and, after its 
discoverer, P. Mantelli. 
