44 JOURNAL OF COMPARATIVE NEUROLOGY. 
mences; and, as the peduncles are broken across there, it is not 
possible to estimate their total length or the shape and size of 
the olfactory bulbs. 
The coronal section formed by its anterior (broken) surface 
gives an isosceles triangle with a base measuring 8:5 mm. and 
sides of 10 mm. each. It expands as it passes backward, so 
that at its junction with the rest of the hemisphere its sides are 
each Ig mm. and its base 16 mm. in length. 
Fic. 2.—Dorsal aspect of the artificial cranial cast of Zeuglodon. Two-ninths 
natural size. a, 4,c,d,as in fig. 1. @, the dorsal rostrum, and 40’, an 
irregular boss on the cerebral hemisphere. (These are probably due to 
imperfections in the cranium.) 
In the artificial cast (fig. 2) all that represents this exten- 
sive olfactory stalk is an irregular rostrum with two small boss- 
like projections, one above the other (a and a). The cerebral 
hemispheres in the natural cast have a broad base, from which 
