3G6 



Dr. W. G. Ridewood on the 



its upper surface about twenty sti'ono; blunt teeth, which 

 engage with the teeth on the cntopterygoids, and with the 

 latter constitute the entire dentition of the animal. The 

 third hasibrancliiul is a small rod-like bone, clearly distinct 

 from the second. The fourth and tifth basibranchials are 



Gonorhynchus Greyi ; hjobrancliial skeleton, dorsal view. The 

 epibranchials and pharyngobvancLials of the right side are not shown. 



bh. Dentigerous plate covering the 



second basibranchial. 

 cb. Ceratobranchial. 

 ch. Ceratohyal. 

 ct. Cartilage. _ 

 eb. Epibranchial. 



eh. Epihyal. 

 gh Glossohyal. 



hb. Hypobranchial. 



hh. Hypohyal. 



pb. Pharj'ngobranchial. 



represented by a rod of cartilage which is continued back 

 for some little distance behind the mesial ends of the fifth 

 ceratobranchials. 



The last two branchial arches are large and slender and 



