Hector.—On the Fossil Reptilia of New Zealand. 851 
9 6.—A humerus corresponding with the characters of this species, but. 
having also the ulna or radius, and some of the smaller paddle bones, is in the 
Canterbury Museum, aecording to Mr. A. MeKay, who thinks the specimen 
came from Heathstock, in the Waipara. 
LEzropoN, Owen. 
This genus was distinguished from Mosasaurus by Owen, by the form of 
the teeth, which are smooth, curved, and slightly compressed, so that in section 
they show an ellipse sharply pointed at both ends, and also by the mode of 
attachment of the teeth to the jaw bone. According to Professor Cope, it is 
abundant in America, being a characteristic fossil of the cretaceous formation, 
four species having been obtained from the western, four from the eastern, and 
two from the southern, cretaceous rocks of the United States ; while the only 
other known species is represented by the jaw fragments found in Europe, and 
described by Professor Owen. The characters of the vertebrz show it to have 
been an exceedingly elongated reptile, one of the American Species, the 
individual bones of which are not larger than those now to be described from 
the Amuri, having belonged to an animal which was not much short of 
100 feet in length. 
10. LEIODON HAUMURIENSIS, n. sp. 
No. 10 a.— This is a portion of a skull of a gigantic species, which I refer to 
this genus on account of the character of the teeth. It consists of the whole 
tooth series of the upper jaw and the corresponding portion of the lower jaw 
of the right side, and the anterior half of the lower jaw of the left side, 
which was worked out from the lower part of the slab. "There are 15 teeth, 
averaging two inches apart, above and below ; the mature teeth rising from a 
distinct elevated crown of cement—characteristic of this genus—while the 
immature teeth push their way through the cement, generally alongside or 
slightly internal to the base of the old teeth. The largest mature teeth have 
a black enamelled crown 1:5 inches in length, slightly curved outwards and 
backwards, compressed laterally with an obtuse anterior ridge, and more 
rounded but still slightly angulate behind, the surface being irregularly striate 
but not channelled. The long diameter of the base is about -9, and the short 
diameter about б, inches. Pulp cavity is filled with rock matrix, and the 
Section shows it constricted where implanted in the dental cement. The internal 
cavity of the tooth shows more lateral compression than the external surface, 
_ It is lined with a black layer, between which and the enamel the dental 
substance is yellowish white. The total length of the tooth series 
the jaws are quite straight and not curved towards the symphyses, and appear 
to have been set at a moderate horizontal angle, so that the muzzle must have 
been long and narrow. | 
is 26 inches ; 
