FAUNA OF THE GOSATJ FORMATION. 



661 



Dinosaurian coracoid occurs in this formation, it may be useful to 

 record the few indications and characters which it displays. The 

 length of the fragment is about 11| centim. ; its breadth is 4. J 

 centim. I infer it to have been a bone, however, fashioned on 

 the plan of the coracoid of Hylceosaurus or Scelidosaurus. The bone 

 thickened considerably towards the articular surface for the humerus, 

 where the greatest transverse measurement is 36 millim., though, 

 being eroded, this may not have been its widest point. The length 

 of the articulation is about 65 millim. ; but, from the state of preser- 

 vation of the specimen, this can only be given approximately. There 

 are some irregularities on the surface which would suggest car- 

 tilaginous covering, such as is indicated by the articular end of 

 the scapula. In length, the surface is slightly concave. Below 

 the articular surface the bone is excavated concavely in length, 

 though the excavation is not very deep. This inferior surface is ob- 

 liquely compressed on the inner side, so that a slight and rounded 

 ridge extends downward from the articular surface on the outer 

 margin of the bone. The excavation extends slightly under the 

 articular surface. The visceral surface is so eroded as to be almost 

 unrecognizable, only one or two patches of unworn bony surface being 

 preserved. The external aspect towards the scapular articulation is 

 roughened with longitudinal ridges. The middle part of the bone 

 appears to be smooth, but carries a row of seven or eight vascular 

 pits close to the elevated and compressed margin of the humeral 

 articular surface, in front of which is a broad shallow furrow, as 

 though the thumb had been drawn over a plastic substance. This 

 furrow becomes wider as it extends downward, and at its distal termi- 

 nation is margined by slight muscular rugosities. Distant 3 centim. 

 from the upper part of the humeral articulation, and rather more, 

 apparently, from the margin of the scapula, was the coracoid foramen, 

 which was about 15 millim. in length and probably ovate or pear- 

 shaped, though its outline is imperfectly preserved. The external 

 surface of the bone appears to have been convex both in length and 

 breadth. The size of the bone can only be inferred from comparison 

 with allied genera. From its imperfect condition I do not feel 

 assured that this bone may not belong to the larger species. 



Bight Scapula* 



This comparatively small bone, though corresponding in a general 

 way with the larger specimens described (see fig. B, p. 656), presents 

 remarkable differences, which enforce the conviction that it belongs 

 to a very distinct species. The blade of the bone is flat, and presents 

 no curvature of plane ; its anterior margin is relatively straighter ; the 

 acromion was smaller and differently placed, and approached almost 

 to the margin of the humeral articulation. As in the other species, 

 the surface for union with the coracoid is eroded, though apparently 

 to no great extent : and though the bone is imperfect at the oppo- 

 site free end, there is no reason to suppose that it extended appre- 

 ciably beyond the part preserved. The extreme length of the spe- 



