1916] 



Dickerson : Tejon Eocene of California 



483 



Dimensions. — Height, 12 mm. ; length, 12 mm. 

 Occurrence. — University of California Locality 672. 



GLYCIMERIS PRESNOENSIS, n. sp. 

 Plate 36, figure 7 



Shell small, cordate, with beak decidedly twisted ; anterior and 

 posterior dorsal margins nearly straight with steep slope to arcuate 

 ventral margin ; decoration consisting of sharp dichotomous ribs. 



This species is also found at the type locality of the Tejon. 



Dimensions. — Length, 7 mm. ; height, 7 mm. 



Occurrence. — University of California locality 1817. 



GLYCIMERIS HANNIBALI, n. sp. 

 Plate 36, figures 8a, 8b 



Shell of moderate size, inflated, with broadly rounded ventral 

 margin and prominent beak. The anterior and posterior dorsal 

 margins are practically straight and parallel to the axis of the shell. 

 The anterior end is nearly straight except for a very slight central 

 concavity at the end of a broad umbonal groove. The posterior end 

 is broadly rounded with greatest arcuity near the dorsal margin. 

 The decoration consists of about thirty flat radial ridges equal in 

 width to their interspaces. The interspaces are decorated by arrow- 

 like marks as in O. sagittata Gabb. Area long, narrow ; interior of 

 ventral margin dentate. 



This species is not orbicular like G. sagittatus Gabb but is more 

 quadrate than this form. It resembles G. veatchi var. major Stanton 

 but its height is less and it is more quadrate, its area is smaller 

 and narrower and the interspaces between ribs are wider. This 

 species grew considerably larger than the type, which is of medium 

 size. 



Named for Harold Hannibal, whose collections of Tertiary fos- 

 sils have greatly aided the study of Tertiary palaeontology. 



Dimensions. — Height, 20 mm. ; length, 22 mm. 



Occurrence. — University of California Locality 672 at the top of 

 the white sandstone member of the Tejon group north of Coalinga. 



LEDA FRESNOENSIS, n. sp. 

 Plate 36, figures 2a, 2b 

 Shell long, rather robust for this genus; beak prominent and 

 situated two-fifths of the length from the anterior end. Anterior 



