42 UPPER CRETACEOUS TELEOSTS 
the dorso-medial regions of each palatine thus providing an articulatory facet for 
those bones. 
The vomer is large and wide although extremely shallow. Anteriorly it tapers toa 
point and is attached to the underside of the extreme anterior end of the meseth- 
moid. The vomer widens posteriorly and its edges are in close association with 
longitudinal ventro-medial facets on the palatines. More posteriorly below the 
lateral ethmoids the vomer tapers and merges into the parasphenoid. The vomer is 
Fic. 18. Cimolichthys levesiensis Leidy. Neurocranium in lateral view. The inset 
shows a diagrammatic representation of the prootic in antero-lateral view. From 
B.M.N.H. number P.181rr. 
toothed in its anterior region, and the teeth are in a median row, there being four 
teeth in all. The bases of the teeth are clearly observable although none of the teeth 
were present on the specimen examined. 
The lateral ethmoids are poorly ossified bones, especially medially. Each is com- 
posed of thin sheets of bone which represent superficial ossifications of cartilaginous 
blocks. Dorsally, each lateral ethmoid is attached to the underside of the frontals, 
and ventrally the only well ossified part of the bone occurs. This is represented by a 
small crenulated knob, in life capped by cartilage, which articulates with a definite 
area at the posterior end of the dorsal region of each palatine. 
The parasphenoid is long and bent through a shallow angle at the base of the 
ascending process. The anterior region of the bone is flattened and expanded 
where it contacts the vomer. The parasphenoid narrows below the orbit and attains 
its minimum width at the base of the ascending process. The ascending process 
passes dorsally and contacts the prootic. The foramen through which the internal 
carotid artery passed into the base of the orbit lies in the ventral region of the ascend- 
ing process. Below this foramen on the ventro-lateral surface of the parasphenoid 
there is a shallow depression with which the pharyngobranchial of the first branchial 
arch articulated. Posteriorly the parasphenoid just contacts the ventral edge of the 
exoccipital and attaches to the ventro-lateral edge of the basioccipital. The para- 
sphenoid ends posteriorly below the hind end of the basioccipital leaving a small 
