178 University of Kansas Geological Survey. 



sphenes of vertebrae rudimentary. Cervical vertebrae seven in 

 number. Thoracic vertebrae not more than fifteen in number, 

 lumbo-dorsals nine or ten ; pygial caudals five or six ; chevrons 

 large, articulated ; spines of caudals regular in length. Limbs 

 relatively large ; arm and leg bones short and expanded ; three 

 or four carpal or tarsal bones present, closely articulating ; 

 pollex and hallux shorter than the fourth digit," divaricated. 

 Coracoid with a deep emargination. Pelvic bones large ; is- 

 chium much expanded distally ; pubis without antero-proximal 

 process. 



The genus Holcodus Gibbes was proposed for the reception of 

 a species supposed by him to be represented by three teeth from 

 Alabama, South Carolina, and New Jersey. Two of these were 

 figured in his work (pi. in, if. 6-9), with the following de- 

 scription: "They are solid, and resemble in their pyramidal 

 form those of Mosasaurus hoffmani antero-posteriorly, the divid- 

 ing ridges making the anterior and posterior surfaces equal, 

 and they are both convex. They are also acutely pointed. In 

 Mosasaurus the outer surface is plane or nearly so, and both 

 have longitudinal narrow planes near the base. . . .In 

 the teeth under notice, on the outer half are many planes, al- 

 most grooves, and also on the inner face, which is peculiarly 

 striated toward the base. As the striated character is a struc- 

 tural distinction, the name Holcodus is given to the genus, and 

 that of acutidens to the species." Professor Leidy afterward 56 

 showed that only the tooth from Alabama belonged to a Mosa- 

 sauroid, the one from New Jersey being that of a crocodile 

 (Hyposaurus) . He describes Gibbes ' s type as follows (op. cit.) : 

 "The specimen has the enameled crown three-fourths of an 

 inch in length. The base is elliptical in transverse section, 

 and measures five lines antero-posteriorly, and four lines trans- 

 versely. The crown is nearly equally divided by acute ridges, 

 which are imperfect in the specimen, but appear not to have 

 been denticulated. The surfaces are subdivided into narrow, 

 slightly depressed planes, and the inner one is strongly striate 



56. Cretaceous Reptiles of the United States, p. 32, footnote. 



