Stewart.] Cretaceous Fishes. 331 



The dentaries bear several rows of teeth, of which those on the 

 external side are minute and somewhat thickly placed, while 

 those on the internal side are large, set upon expanded bases, 

 and are well separated from each other. The outer surface of 

 the dentary is covered with numerous well-marked sulci. The 

 cotylus is bifurcated in the center, each half appearing as a 

 Bmall hemispherical pit. There are several other tooth-bearing 

 elements, among which is a long, slender bone with a single 

 row of small conical teeth on the lower side, which probably 

 represents a premaxilla. 



The top of the skull is elongated and somewhat triangular in 

 outline. It is especially remarkable for the great extent and 

 delicate markings of the frontals, as well as of the other bones 

 of this region. The supraoccipital is small and enters slightly 

 into the formation of the top of the skull. The parietals are 

 small and do not extend farther forward than the anterior ex- 

 tremity of the supraoccipital. 



Throughout the whole extent of the top of the skull there is 

 a close resemblance to the corresponding portion of Stratodus, 

 the principal difference being found in the larger size of the 

 parietals and their meeting along the median line. 



There is one specimen at hand that has the vertebral column 

 preserved completely, and another one nearly so, from which 

 we see that there were altogether about fifty-three vertebra*. 

 Those in the cervical and dorsal regions are finely striated, 

 while those near the end of the tail are deeply grooved on the 

 sides, the grooves commencing on the eighth or ninth vertebra 

 from the end of the series. The neural canal is bounded by a 

 lamina of bone on each side, outside of which the neuropophyses 

 rise and form a vertical ridge on the side. The haemal canal 

 is bounded by laminae similar to those described above. The 

 haemal arches are located outside of these, so that in a detached 

 vertebra it is often difficult to determine the two sides. 



In Cope's description of the vertebral column of E, nepxolica* 9 

 he says that up to the fourteenth vertebra the neural canals arc 

 not bounded by vertical laminae : in this I cannot agree with 



»9. Cret. V ; . 2:tf. 



