On a New Species of Scyrnnognathus (S. tigriceps). 31 



girdle resembles the Therocephalian type as seen in Ictidosuclius 

 primaevus. 



The scapula has a bi^oad lower end, and forms the upper half of 

 the glenoid cavity, which half is almost a plane surface bounded 

 by rather more than a semicircle. In its length it is curved back- 

 wards and inwards. The precoracoidal foramen is seen passing 

 down from the inner side of the scapula, where it forms a 

 moderately deep groove, and appears on the outside just below 

 the suture between the scapula and precoracoid. The right pre- 

 coracoid was found broken in such a way as to show the position 

 and direction of the precoracoidal canal. The scapula possesses 

 no acromion process, and there is no trace of a cleithrum. As a 

 loosely articulated cleithrum exists in the allied Scylacops capensis 

 it is more probable that it has been lost than that none existed. 



The coracoid forms the lesser and lower half of the glenoid cavity, 

 the glenoid surface being concave, looking upwards and outwards, 

 and being separated from the outer side of the bone by a pro- 

 minent ridge. Posteriorly, the subglenoid portion is prolonged 

 into a process which curves slightly upwards and whose thickness 

 rapidly diminishes. On the left coracoid this process has been 

 compressed upwards and backwards. 



The precoracoid is a thin plate-like bone which is anchylosed with 

 both the other elements. It is slightly smaller than the coracoid. 

 The suture between the two ventral elements appears to be a 

 straight one, and the precoracoid appears to form no part of the 

 glenoid cavity. 



The chief measurements are as follows : 



Greatest length of scapula 130 mm. 



Width of base of scapula 80 ,, 



Width of top of scapula 49 



Greatest width of glenoid 43 ,, 



Greatest height of glenoid 48 ,, 



Length of precoracoid coracoidal suture 70 , , 



Length of coracoidal process behind glenoid 84 , , 



Distance between anterior and posterior edges of precoracoid 64 ,, 



The clavicle is a slightly curved bone, flattened from above at its 

 upper end, oval in the middle, and expanded into a wide, flat plate 

 at its articulation with the interclavicle, being thickest there an- 

 teriorly, and thinning out to about 1 mm. behind. The two clavicles 

 do not meet. The total length of the left clavicle is 200 mm., and 

 the greatest width at the proximal end 45 mm. 



