CHONDROCRANIUM OF EUMECES 197 
posterior origin from the olfactory lobes. They extend, with 
little or no branching, into the forward part of the nasal capsule, 
where they break up very suddenly into numerous small branches 
leading into the nasal epithelium. . They correspond unquestion- 
ably to the ‘olfactory nerves’ as modeled by Turner (714) from 
the same sections, as figured by Watkinson (’06) for adult 
Varanus, and as described in the general texts; they are appar- 
ently the ‘vomeronasal nerves’ as distinguished by McCotter 
(12, ’17). The details of their distribution and their relation 
to the smaller nerves have not been followed out, but seem to 
agree with the observations of McCotter, particularly for the 
Mammalia (’12). 
Leading from each orbit into the nasal cavity, and separated 
from the fenestra olfactoria only by the sphenethmoid cartilage, 
is an irregular slit, the fissura orbitonasalis (fig. 3, fis.o-na.), 
through which the ethmoid ramus of the trigeminus gains access 
to the nasal chamber. Entering this chamber ventral to the 
olfactory lobe, it makes its way to a position above and to the 
side of the group of olfactory nerve bundles; here it divides into 
two branches (fig. 25, n.V.eth.e. and n.V.eth.t.). The external 
ramus passes on with little change of direction, emerges through 
the small foramen epiphaniale noted above the aditus conchae. 
(fig. 26,n.V.eth.e.andf.ep.), and supplies the region of the glandula 
lateralis nasi. The ramus interna sweeps across the nasal cavity, 
dorsal to the olfactory nerve bundles, and reaches the septum; 
it then descends rapidly along the septum to the level of the 
septomaxillary bone, and follows the median margin of this 
bone forward, finally emerging through the foramen apicale at 
the tip of the snout (fig. 1, e.ap.). Its course is easily traced by 
comparing its position (n.V.eth.2.) in figures 25, 26, and 28. 
The arrangement of these openings and the distribution of 
the nerves is essentially alike in Lacerta and Kumeces; in other 
reptiles some rather striking variations are recorded. Thus, 
the sphenethmoid cartilage is lacking in Crocodilus (Shiino, 714) 
and Vipera (Peyer, ’12), and the fenestra olfactoria and fissura 
‘orbitonasalis become perfectly confluent. Among the turtles 
Nick (’12) has reported very marked differences in this respect; 
