78 Edwin Chapin Starks. 



Exoccipitals (except in Scombrinse) broadly meeting over basi- 

 occipital. 



Prefrontals broadly united at the median line ; each pierced for the 

 passage of the olfactory nerve. 



JSTo auditory bulla apparent externally. 



Temporal crests well developed, and reaching at least to above 

 middle of eyes. 



Myodome large and opening posteriorly to the exterior. 



Opisthotic (except in Scombrinse) interposed between the pterotic 

 and exoccipital, and the lower limb of the posttemporal attached to 

 its upper surface. 



Basisphenoid present, and with a process descending to the 

 parasphenoid. 



Eye with a bony sclerotic case. 



Suborbital ring incomplete, and without a sensory tube (except in 

 Scombrinse) . 



Nasal bones well developed. 



Process of premaxillary short, heavy, and triangular, and abutting 

 immovably against the ethmoid. 



Maxillary with an auxiliary element on its upper edge. 



Preopercle unarmed with spines, and all of the opercular elements 

 j&tting closely together to fonn a broad smooth plate. 



Head of hyomandibular where it articulates with cranium divided 

 into two parts. 



Teeth of jaws fitting into alveoli.^ 



Pour pairs of superior pharyngeals present ; the third and fourth 

 on each side sometimes joined (not anehylosed) to form a more or 

 less complete single plate. 



Three basibranchials present ; the first remote from the hypohyal 

 of the first arch, and hooked under the glossohyal. 



Clavicle not developed much above pectoral fin, placed very oblique 

 and sloping forward, beyond the hypocoracoid. 



Actinosts four in number ; short and broad ; two and a half of 

 them on the hypercoracoid. 



*This character is appreciable only in the forms with moderate or large 

 teeth. 



