82 



THE EXTINCT BATRACHIA, REPTILIA 



Width of palate, 



Height of os maxillare at middle, 



Thickness of palatine suture of o. maxillare, 



Cretaceous Green Sand of New Jersey. 



Lines. 

 18.5 

 14. 

 2.5 



IfVI'OSA URUS FRATERCTJLUS, Cope. 



Spec. nov. 



This small species seems to be clearly indicated by a portion of the ramus mandibuli containing three and half a 

 fourth alveoli, and two perl eel, teeth. These parts are less than half the size of those of the smaller individual of H. 

 rogersi, whose maxillary hone and teeth are described in the preceding article. The crowns of the teeth are shorter 

 and more compressed than those in the corresponding part of the jaws in H. rogersi ; they are marked with a coarse 

 obtuse fluting to near the tip, with a finely striate enamel as in Holops glyptodon ; in those of II- rogersi, the enamel 

 is smooth and ridged by line keels, which <1« t extend more than hall' the length of the crown. 



That the animal of which 1 describe this fragment was not the young of the larger Hyposaurus, is, I think, 

 indicated by the deep grooving and strong ridging of the dense layer of bone of the ramus; by tho minute pulp 

 cavity of the. crowns of the teeth, and by the well developed suocessional tooth in the fang of one of the latter, whose 

 apex has nearly reached the alveolar margin. That, tin; individual is not fully grown is probable, but that it is of 

 smaller species than the II. rogersi, there appears to be little room for doubt. 



The ramus is scarcely flattened below, as is the case with most gavials, and the depth at the symphysis is equal 

 the width of each ramus. Sculpture in deep longitudinal grooves slightly inosculating. Teeth directed very little 

 outwards: their fangs and crowns are considerably compressed ; the antero-posterior cutting edge is stronger than 

 the ridges, and does not diminish to the base of the crown. Viewed from within flic form is symmetrical and 

 straight ; from behind theircrown is greatly incurved. The outline of the crown from within is an isosceles triangle, 

 the width, more than .66 the height. Ribs on the inner face;, seven, on the outer, eight. A few teeth in the jaws 

 of ][. rogersi are as short and broad as those bene described, but they are not found in the middle of the series as in 

 this species, but probably belong in the posterior alveoli, as occurs in some alligators. 



Length of fragment, 



Width at middle, 



No. of alveolae in an inch : three and half and interspace. 



Length tooth above alveolus, 



" crown of tooth, 

 Width " " at base, 



Lines. 

 19.8 



(!. 



4. 



2.75 



1.75 



from the middle Green sand bed at Birmingham, Burlington, (Jo., N. .1. Presented to the Academy by Judson 

 C. Ga.sk ill. 



INCERTAE SEDIS. 



The following species probably belongs to the Amphicoeli, but to what genus cannot well be determined, as 

 nothing but the teeth are known. 



CROCODILUS LIU M I LI S, Leidy. 



Trans. Amer., Phil., IHCfl, p. 140. Tab. 

 Bad Lands of the, Judith River, Nebraska. 



