126 FIELD COLUMBIAN MusEUM—GEOLOGY, VOL. II. 

eEny) 
Fic. 1. Mandible of Vyctosaurus gracilis, x %. 1, from above; 2, from below. 
MEASUREMENTS OF MANDIBLE, 
mm 
Length, as preserved -s-..2-¢-.---L---3 ----4... .j 200 a 168 
Lengths of rami to hind margin of floor_----_ -...__ --_ [os gee 78 
Width between condyles__----..-_..--<---_L.._2. 5 39° 
HOLDS: 
Two slender, cylindrical, gently curved bones, about thirty millime- 
ters in length, were found lying side by side beneath the anterior part of 
the skull. They are sufficiently well shown in Plate I of the paper cited 
in the Journal of Geology. Lying near the occiput in the same plate, is 
seen a small, triangular, or V-shaped bone which I then thought might be 
