DIPLOCAULUS MAGNICORNIS 33 



These are almost universally known as the 'slime canals of the 

 Stegocephala/ a decided misnomer since the lateral line canals 

 have nothing to do with the production of slime. The canals 

 were also detected on the mandible which is associated with the 

 present skull. On the right of the skull (fig. 1) there will be 

 seen a distinct groove which runs along the edge of the skull. 

 This canal had been called by Allis in Amia "the anterior portion 

 of the infraorbital." There were also detected portions of the 

 supraorbital canals but the skull is so badly crushed that it is 

 impossible to follow the complete course of the canals. 



The palate of the skull, as here given, is an advance over any- 

 thing heretofore known. There still remains much to be deter- 

 mined in regard to its structure, but the following is offered 

 as a contribution to the more complete knowledge of the subject. 

 Cope, in 1895, gave a figure of the anterior portion of the palate 

 and Broih, in 1902, gave further notes on its structure. Broili, 

 however, had but a small portion of the skull of the animal on 

 which to base his conclusions. Unless there be an extreme varia- 

 tion in the shape assumed by the skull of this species Broili's 

 restoration is at fault in regard to the posterior curve of the skull, 

 there being no indication of such a condition in the present speci- 

 men, nor in the species D. limbatus Cope. Cope gave very accu- 

 rately the positions of the teeth on the palate but was unable 

 to determine the elements which bore the teeth. In the present 

 skull the tooth-bearing elements are found to be the premaxillae, 

 the maxillae, the vomers, the palatines and the transverse bones. 



There are five pairs of openings and depressions on the palate 

 of the skull. These are: the internal nares, correctly repre- 

 sented by Cope and Broili; the palatine vacuities; the depressions 

 which Broili calls the * Ohrenschlitzgruben' or auditory fossae : 

 the infratemporal foramina and depressions along the posterior 

 lateral border of the palate which appear to be partly due to a 

 folding over of the skull elements and doubtless gave place for 

 the attachment of the masseter and temporalis muscles. The 

 arrangement of the palatal openings of Diplocaulus does not 

 differ in any essential respect from the condition found in the 

 larger Stereospondylia. 



JOURNAL OF MORPHOLOGY VOL. 23, NO. 1 



