224 UPPER CRETACEOUS TELEOSTS 
because of its abdominal pelvic fins cannot be included within the Ctenothrissi- 
formes. Thus Nematonotus emphasizes the basal convergence of the ctenothrissi- 
form and myctophiform lineages, and for the time being is best included in the 
Salmoniformes as a separate suborder, Nematonotoidei. 
hy6 
u2 
Fic. 96. Nematonotus bottae (Davis). Caudal fin skeleton in lateral view. 
A further genus considered by Woodward (1901) to be a myctophiform is Acro- 
gnathus. In many respects this resembles Sardinioides, notably in respect of the 
caudal skeleton, but the maxilla, although apparently untoothed, is expanded 
posteriorly and enters the gape behind the premaxilla. The maxilla also supports 
two large supramaxillae. The large size of the basal fulcral scales recalls Sardimioides 
and Aulopus, but not the Ctenothrissiformes in which the fulcral scales are reduced. 
An adipose fin could not be made out in Acrognathus but the pelvic fins are abdominal. 
Perhaps Acrognathus is best included with Nematonotus in the suborder Nematono- 
toidei, which lies very close to the group from which both the Myctophiformes and 
the Ctenothrissiformes were derived. 
The last of the Cretaceous genera considered by Woodward (1901) to be a scopeloid 
is Sardinius. The species Sardinius cordieri von der Marck (Text-fig. 97) certainly 
shows several myctophiform characters which are comparable with Sardinioides and 
Aulopus. For instance the maxilla is excluded from the gape, the ascending process 
is abbreviated (as in Aulopus), the suboperculum is large and the operculum is 
small, preural vertebra one is fused with ural vertebra one in the caudal skeleton, 
and the neurocranium is shallow. 
