Stewart.] Cretaceous Fishes, 383 



MUGILIDiE. 



The family Mugilidse is represented in our collection by only 

 one genus, Syllsemus, and it is very doubtful if this belongs 

 to it. In fact, it presents some characters which evidently do 

 not belong to this family, which are the presence of the lat- 

 eral line and more than four spines in the anterior dorsal fin. 

 There are also more than twenty-four vertebra^, but it seems 

 likely that this could hardly be called a family character. On 

 the other hand, the absence of teeth seems to point to the Mu- 

 gilidse, and for the present, at least, I think that it should be 

 left in this family until more complete specimens are found 

 which will determine its exact position. 



SYLL^GMUS. Plate LXXII, fig. 2. 

 Syllazmus Cope, Rep. U. S. Geol. Surv. Terr., vol. n, p. 180. 



Cope has characterized this family as follows: 140 "A short, 

 spinous dorsal fin. Ventral fins abdominal, posterior to the spi- 

 nous dorsal. Pectoral fins subinferior in position. Coracoid 

 bones forming a compressed, keeled body. Scales large, cycloid ; 

 lateral line present, extending along the middle of the sides. 

 Parietal bones less than epiotics, entirely separated by the 

 supraoccipital. Frontal bones large, wide, their common suture 

 distinct. 



" The opercular apparatus extends obliquely backward, while 

 the mandible is produced forward. Hence the inferior part of 

 the hyomandibular and the symplectic are directed obliquely 

 forward. The opercular bones are, and their inferior borders 

 reach the median line of the inferior side of the head." 



The body is covered witli moderately thick scales, which are 

 covered with fine concentric stria 4 . The mandible is short, and 

 the dentary apparently toothless. In some respects our speci- 

 mens do not agree with Cope's, for there are evidently two 

 dorsal fins in one of the specimens, which are separated from 

 each other by a short space. The anterior of these is well de- 



140. Rep. U. S. Geol. Surv. West lOCth Mer., vol. IV, lsTT, p. 26. 



