Prof. Owen on the genus Dicynodon. 75 



DiCYNODON (?) STRIGICEPS. (PI. VI. figS. 2 & 3.) 



This species is founded on the anterior or rostral part of a skull of a Dicyno- 

 don(?), which, in proportion to its height and breadth, is as much shorter than that 

 of the Dicynodon testudiceps, as this is in comparison with the skull of the Dicynodon 

 lacerticeps. The breadth of the inter-orbital space is equal to that in the Dicynodon 

 lacerticeps, but it is more concave ; it is less than that of the Dicynodon testudiceps, 

 and there is no median longitudinal rising, as in that species. The breadth between 

 the upper and posterior part of the nostrils is equal to that in the Dicynodon testu- 

 diceps ; but the rostral contour, continued from the horizontal inter-orbital tract, 

 describes, in descending, a semicircular curve, convex forwards, and with the lower 

 part bending back to form the alveolar, or rather edentulous trenchant anterior 

 border of the mouth. 



This form of muzzle not only distinguishes the present species from its con- 

 geners, but is unique in the Reptilian class. The orbits, o, fig. 2, with prominent 

 anterior borders, are thus brought close to the fore-part of the head ; the nostrils, n, 

 instead of being in front of the orbits, are beneath them : the physiognomy of 

 the old reptile must have resembled that of the Owl, with its horny beak curving 

 downwards and backwards from between the advanced staring eyes ; and I have 

 indicated this resemblance by the proposed specific name. The outer surface of 

 the convex internasal ascending process of the intermaxillary is smooth, entire, 

 showing a slight median longitudinal prominence : the peculiarly shortened muzzle 

 of the Dicynodon strigiceps cannot be the effect of accidental fracture, for this would 

 have carried away the fore-part of the alveolar border of the intermaxillary bone, 

 and have left a vacuity between the lateral borders ; but the anterior boundary 

 of the palate is complete, fig. 3. This boundary does not describe so true a 

 semicircle as in the Dicynodon testudiceps, but is semi-elliptic, being narrower 

 across the commencing expansions, c, c, apparently of the alveoli, in proportion 

 to the distance from that transverse line to the fore-part of the alveolar border. 

 The reverse of this might have been expected from the extreme shortness of the 

 muzzle, but it is due to the more posterior position of the thickened parts of the 

 superior maxillary bones in the Dicynodon strigiceps. In the two preceding species 

 the tusks project from beneath the fore-part of the orbit, or between this and 

 the nasal opening : if the present species possessed the tusks, they must have pro- 

 jected opposite or from beneath the back part of the orbit, the floor of which is 

 remarkably prolonged backwards and outwards ; but the mutilation of the skull at 

 this part has destroyed its true generic character. The pre-frontal bones are 

 unusually developed, and descend lower than usual to form the anterior pro- 

 minence of the orbits ; the facial plates of the superior maxillary bones inchne 



