AND MESOZOIC FISHES. 
445 
by the fourth; while the fifth is half as large again as the fourth. The sixth and 
last is a little smaller than the fifth. The teeth of the fifth row are as small a.s 
those of the first and second rows, and extend posteriorly to the anterior part of 
the fourth row, and not beyond. The crowns of the teeth are perfectly smooth 
and without keel or depression. 
Measurements. 
MM. 
Length of tooth series ; 17 
“ “ six teeth of external row ; 10 
“ “ six teeth of third row ; ILo 
“ “ six teeth of fourth row ; 1 0‘5 
^ X- f anteronosterior ; 3 
Diameters ot fifth of fourth row 1 
( transverse ; t 
The horizon of this species is not exactly known, but it is probably Lower 
Cretaceous or Neocomian. It gives me much pleasure to dedicate it to Dr. E. T. 
Dumble, Director of the Geological Survmy of Texas, through whom 1 received the 
specimen. 
URANOPLOSUS Sauvage. 
Uranoplosus aectatus sp. nov. Plate XX, Fig. 8. 
Represented by a vomer which supports five rows of teeth in good couditiiin. 
I refer it to the genus Uranoplosus of Sauvage,' since it presents the characteristic 
peculiarity of the inferior surface. This presents three planes, a median and two 
laterals, which subtend an angle of the dental face on each side of the median row 
of teeth. These angles divide the grinding face of the most anterior tooth of tliat 
row preserved, but fall outside of the posterior teeth. But six teeth of the median 
series are preserved, and five of each of the laterals. 
There are but five rows of teeth; the small intercalated teeth found between 
the larger lateral rows in the type of the genus, U. cotteaui Sanvg..' being al> 
sent. The teeth of the median row are enlarged transversely, being about twice 
the diameter of those of the adjacent lateral series. Their anterior and posterior 
border’s are nearly sHaight, and their grinding faces show, where unworn, a sliallnw 
transverse groove. The teeth of the first lateral series alternate or not with those 
of the median row, and are a little wdder than long. Their anterior borders are a lit- 
tle concave, and the posterior convex, and continuous with the lateral conve.x bor- 
der. The crowns are slightly concave w’hen imwmrn. The temth ol the external 
row have the outlines of the crowns snbi’ound, and a little smaller than those of tlie 
first row; convex posteriorly, and a little concave anteriorly. All the crowns of 
the vomer touch each other, with a few slight exceptions. 
' Bulletin Society des Sc. hist, et nat. del’Yonne 3d Ser. T. I, p. 47. 
2 Loc. cit., PI. I, Fig. 1. 
