76 The Alligator and Its Allies 



of this process is a concavity that looks like another 

 articular surface. Laterally the articular articu- 

 lates with the supra-angular ; ventrally and poste- 

 riorly with the angular. 



The angular (Fig. 23, 20, Fig. 21, 22) forms the 

 ventro-posterior border of the jaw and of the 

 external mandibular foramen. Its narrow, poste- 

 rior end forms a part of the prominent process men- 

 tioned in connection with the articular. Between 

 it and the posterior edge of the splenial is the 

 internal mandibular foramen, which is much smaller 

 than the external (Fig. 23, 28). Anteriorly the 

 angular articulates with the dentary, coronoid, 

 and splenial; dorsally with the supra-angular and 

 the articular. 



TheHyoid (Fig. 25). The hyoid being mainly of 

 cartilage is usually not seen in prepared skeletons. 

 It is thus described by Reynolds: 



'The hyoid of the Crocodile consists of a wide 

 flattened plate of cartilage, the basilingual plate 

 or body of the hyoid, and a pair of cornua. 



"The basilingual plate (Fig. 25, i) is rounded ante- 

 riorly and marked by a deep notch posteriorly. The 

 cornua (Fig. 25, 3), which are attached at a pair of 

 notches near the middle of the outer border of the 

 basilingual plate, are partly ossified, but their ex- 

 panded ends are formed of cartilage. They pass 

 at first backwards and then upwards and inwards. 

 They are homologous with part of the first bran- 

 chial arches of Selachians." 



