Fierce ge omnmnnir 
9 
1871.] 269 [Cope 
A fine specimen of this species was found by Martin V. Hartwell near 
Fossil Spring. Portions of a second were found by Lieut. Jas. H. Whit- 
ten on a bluff on Butte Creek. 
Both the above species are the most elongate in proportion to their 
diameter of the order. They are larger in their dimensions than those 
next enumerated. 
EDESTOSAURUS DISPAR, Marsh. 
Amer. Jour. Sci. Arts, June, 1871. Smoky Hill River. 
EDESTOSAURUS VELOX, Marsh, 1. c. 
Near the North Fork of the Smoky River. 
HOLCODUS, Gibbes, Cope emend. 
Vertebree without the zygosphen articulation. Palatine bones flat, 
alate, its teeth not unequally exposed at the bases, or not pleurodont. 
This genus bears the same relation as regards the palatine bones and 
teeth, to the genus Liodon that Olidastes does to Edestosaurus, as above 
defined. The structure of the caudal vertebrae I unfortunately cannot 
ascertain, and therefore do not know whether they are as in Olidastes or 
Liodon. It differs from Mosasaurus as it does from Liodon, i. e. in the 
horizontal laminiform palatines. 
The name which I use for this genus was originally applied by Dy. 
Gibbes* of Charleston to a species represented by teeth from the creta- 
ceous of Alabama, but of which no other portions were known. The 
teeth of the Kansas species now referred to this genus, are very similar 
in character to those described by Gibbes, so much go as to lead me to 
believe that when other portions of the H. acutidens of that author are 
known, they will be found to display the more important features here 
regarded as truly distinctive of the genus. Its place is evidently between 
Clidastes and Liodon, the pterygoid bones being those of the former, and 
the vertical articulations being identical with that characteristic of Lio- 
don. In all of the species, traces of the zygosphen appear, but in the:H. 
coryphaeus, Cope, the rudiment amounts to a short process directed for- 
wards at the base of each anterior zygapophysis. 
The species known as yet are of medium size in the order. 
HoLcODUS CORYPHAEUS, Cope, sp. nov. 
Characters. Cervical and dorsal vertebre with the articular surfaces 
depressed transverse, slightly excavated above for the neural canal. 
The diapophyses not continued inferiorly to the rim of the cup, on the 
cervical vertebre, and not receiving from it a cap of articular cartilage. 
Occipital crest much elevated, quadrate bone small, the meatal pit de- 
pressed between bounding ridges above and below. Rudimental zygos- 
phen not uniting into a keel above. Teeth slender less curved than 
H. ictericus. 
Description. This species is chiefly based on one specimen, which in- 
*The Mosasaurus and allies: Smithsonian Contr. to Knowledge, 1851, 9 Plate. 
