( 268 ) 



In Cabalas sylcestris the beak is relatively much longer, and the same is the 

 case to a still greater extent in Erythromachus. In Uypotaenidia the nostril is 

 shorter and is continued anteriorly as a groove on the side of the beak. 



Except for its greater curvatuie, the mandible is very like that of Ocydromits. 

 The posterior angular process is, however, a little more prominent. In the specimen 

 described a short bony process projects backward from the symphysis between the 

 mandibular rami. 



The dimensions of the skull described are given l)elow (measurements of the 

 skulls of several other rails are added for comparison) : — 



The vertebral column in the specimen described appears to be comi)lete. It 

 consists of thirteen vertebrae with fused ribs (true cervicals) and nine with free ribs, 

 of which the anterior two are probably cervico-dorsals and the remaining seven true 

 dorsals : this vertebral formula is the same as that of Ocydromxis and Uypotaenidia. 

 The individual cervicals are broader in proportion to their length than in Hypotaenidia, 

 and correspond most nearly to those of Ocydromiis, as indeed do the other vertebrae. 

 When the whole twenty-two free vertebrae are articulated in a straight line the column 

 measures about 167 mm. in length. 



The paired catapophyses are well developed on vertebrae 6 — 10, and gradually 

 approach one another till they nearly enclose a carotid canal. On the 11th 

 they are replaced by a median haemapophysis which is repeated to the 17th, on 

 which it is bifid. The sides of the centra of 12 — 15 are perforated by pneumatic 

 foramina. 



The sternum (see PI. X., figs. 5, 6) is in many respects intermediate between 

 those of Ucydrornva and Ilyjjotaenidia. As in the former, the coracoid grooves are 

 separated from one another in the middle line by a considerable interval, which 

 is occupied by a deeply concave thickened border, the spina e.ctenia being quite 

 obsolete; in Uypotaenidia, on the other hand, the coracoid grooves nearly meet 

 in the middle line, and there is a well-developed simple spina externa. In the 

 height of the keel the sternum comes e.xactly midway between the two genera 

 mentioned. The reduction of the keel is accompanied by a shortening of the body 

 of the sternum, which no longer extends as far back as the xiphoid processes, 

 as in Ihjputavnidia, and is irregularly notched in the middle line ; the apex of 

 the keel, though thickened, is not bifid as in Ocydroiniis. Comparison of this 

 sternum with that of Cabalus modestus figured by Hutton shows that the 

 differences between them are very great, greater indeed than between it and the 

 sternum of Ocydrvmus. In Cabalus modestus the keel is almost obsolete, the 

 coracoid grooves more widely separated, the whole bone wider in proportion to its 



* Taken from the occipital cumlylc to the tip of the beak. 



