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bulletin: museum of comparative zoology. 



the cranium (Fig. G). The cartilage extends along the outer side onlj', 

 as we should expect it to, of the splenial, for a distance equalling at 

 least the depth of the bone it is attached to. Originally it may have 

 extended for an even greater distance anteriorly, })ut in the actual 

 condition of the specimen this cannot be determined positively. The 

 usual groove which is presumed to have been occupied by a remnant of 



Fig. G. — DlnomijLii.^toiaa bttclierl Eastman. (Juailicd articular cartilage belonging to 

 t3'pe specimen, detaclied from outer face of right mandibular ramus; found in position 

 corresponding to that shown in Plate 4, Fig. 23. 



Meckel's cartUage is present along the inferior margin, its direction and 

 position being as in Dinichthys and other Coccosteans. 



Both of the vomerine teeth are present, and are readily identifiable 

 as such on account of their strong resemblance to the corresponding 

 elements of Dinichthys. Their extreme tips are broken away, but it is 

 evident from the cross-section of the fractured part, as seen from the 

 oral surface (Plate 1, Figs. 4, 5 ; Plate 2, Figs. 13, 14), that they must 

 have been prehensile to about the same degree as the symphysial beaks 



