Notes on the Osteology of Anogmius 

 Polymicrodus Stewart. 



Contribution from the Paleontological Laboratory No. 44. 



BV ALBAN STEWART. 



With Plate XXXI. 



This species was first described by myself as Bt-ryx f polyDticrodiis, 

 from some remains of the tooth-bearing elements collected in west- 

 ern Kansas several years ago, but as this material was poor, no 

 general idea of the anatomy of the animal could be obtained. 

 During the past summer the geological expedition to western Kan- 

 sas was fortunate enough to secure the remains of several speci- 

 mens of this species from the Butte Creek region of Logan county, 

 and in addition to this, was loaned an almost complete specimen 

 by Mr. Travis Morse, of lola, Kansas. From all of the above 

 specimens a very fair idea of the anatomy of this species can be. 

 obtained. 



The bone called premaxilla in the preliminary description of this 

 form* is evidently not a premaxilla, but some other bone the loca- 

 tion of which I have been unable to discover. The premaxilla is 

 rather short with a semi-elliptical band of teeth, below which it is 

 covered with numerous rows of villiform teeth, all of which seem 

 to be directed inward. Above the tooth-band, on the external 

 side, there is a thin wall of bone extending upward which is cov- 

 ered with coarse longitudinal strife on the posterior portion, while 

 the anterior part is covered with minute tooth-like projections 

 which extend backward for some little distance just over the tooth- 

 band. The internal side of the bone is deeply concave and was 

 doubtless united very loosely with the maxilla, allowing it to be 

 freely moved. The two bones were probably very loosely united 

 with each other anteriorly, if at all. 



The maxilla is moderately long and thin transversally toward the 



*Kan. Univ. Quar., Vol. VII, p. 195. 



(117) KAN. UNIV. QUAR., VOL. VIII, NO. 3, JULY, 1899, SERIES A. 



