[LAMBE) | ON A NEW CROCODILIAN GENUS 227 
is behind, reaching downward to within a short distance of the upper 
edge of the foramen magnum. Meeting in the median line above the 
foramen magnum and forming the upper and lateral boundaries of that 
opening are the large exoccipitals which meet the basioccipital below and 
are produced laterally over the jugals in an extensive sutural union. The 
exoccipitals are prolonged downward, at their inner ends, exterior to the 
basioccipital. This latter bone forms the lower boundary of the foramen 
magnum and is deeper than broad, its upper half lying between the 
downward extensions of the exoccipitals. In the occipital view the 
basisphenoid is almost completely hidden by the basioccipital. Between 
these two bones at their lower extremities is the opening of the median 
Eustachian canal, M.E.C., plate II, fig. 3. Four foramina pierce the 
exoccipital ; of these, three are close together in line with the mid-height 
of the foramen magnum. ‘They are, in order receding from this open- 
ing, the foramen for the hypogiossal nerve, XII, fig. 3, the foramen for 
the vagus or pneumogastric nerve, X, fig. 3, and one, the largest, for 
the facial nerve, VII, fig. 3. Near the lower extremity of the ex- 
occipital is the foramen for the entry of the internal carotid artery, 
CAS: 
The position of the external auditory meatus, leading into the 
tympanic cavity is seen at c.a.m., plate III, fig. 9. The specimen here 
has suffered considerable damage so that the intricate structure of this 
part of the cranium cannot be satisfactory made out. 
Leading back from the tympanic cavity is a canal through which 
passed the cartilaginous rod that during tbe life of the animal was; 
continuous with Meckel’s cartilage in the mandible. The floor of this 
canal is seen at e, plate II, fig. 3 and plate III, fig. 9, in the upper 
surface of the quadrate. This canal thus has its exit behind between 
the quadrate and the lateral wing of the exoccipital as in modern alli- 
gators and crocodiles. 
In side view, the occiput, leaving out of consideration the occipital 
condyle (which is broken off from the specimen), extends farthest back 
in the neighbourhood of the foramen magnum; the upper half, which 
_is concave, inclines decidedly forward up to the parietal, and the lower 
half to a somewhat greater extent forward in passing down to the lower 
extremity of the basioccipital. Viewing the specimen from this 
standpoint the basisphenoid appears on the surface as a narrow strip 
of bone between the pterygoid and the basioccipital below, and the 
quadrate and basioccipital above. It reaches farther down than the 
basioccipital and ends above, in contact with the quadrate, in line with 
the floor of the foramen magnum. The quadrate extends downward 
