8 



ON THE SKULL OF HANA TIGRINA. 



floor of the nasal capsule uncovered. The outer border presents 

 two notches, the posterior one bounding the posterior nares. 

 The vomerine teeth are situated in an oblique line along the 

 posterior border. 



The Squamosals (text-figs. 1, 3, 4, & 5, s.) are strongly deve- 

 loped. From the posterior half of the cross-bar is given off a 

 horizontal shelf-like process covering the tegmen tympani and 

 extending inwards along its posterior border as far as the 

 junction of the prootic and the exoccipital. 



The Pterygoids (]Jt.), Palatines (p.), Quadrato-jugals (q.j.), 

 Maxillce (m,), bones of the lower jaw and the hyoid apparatus 

 are of the usual type. An interesting feature, however, is the 

 presence of three well-marked depressions on the ventral side of 

 the upper jaw in its anterior portion (vide text-fig. 2). The 

 middle one of these depressions is between the two premaxillse ; 

 it receives a corresponding median projection from the mento- 

 meckelians. The two lateral depressions are at the junction of 

 the premaxilla with the maxilla of each side ; each accommodates 

 a strongly developed projection of the dentary of each side. 



Literature cited. 



1. Nicholls, George E. — A Note on the Urostyle (os coccygeimi) 



of the Anurous Amphibia. Proceedings of the Zoological 

 Society of London, 1915, p. 239. 



2. Nicholls, George E. — Some Notes upon the Anatomy of 



liana tigrina. Proceedings of the Zoological Society of 

 London, 1915, p. 603. 



3. Parker, W. K. — On the Structure and Development of the 



Skull of the Common Frog (Rana temporaria L.). Philo- 

 sophical Transactions of the Roval Society of London, 

 1871, vol. 161, p. 137. 



4. Parker, W. K. — On the Structure and Development of the 



Skull in the Batrachia. — Part III. Philosophical Trans- 

 actions of the Royal Society of London, 1881, vol. 172, 



p.i. 



