452 



MR. C. TATE REGAN ON THE 



other as in Lepidosteus, differing only in form and proportions ; 

 owing to tlie shortness of the snout the prsemaxillaries are 

 scarcely exposed on the upper surface behind the nasals, and 

 when the nasals and adnasals are removed it is seen that the long 

 tubes that carry the olfactory nerves in Leiyldosteus are repre- 

 sented by mere foramina. 



The i^ostral cartilage contains paired septo-maxillary and lateral 

 ethmoid ossifications ; the vomers and parasphenoid are broad 

 and flat, and the latter is unconnected with the frontals ; the 



Text-figure 6, 



COT^- 



SpO' 



corl 



epo' ^ 

 eoc 



Amia calva. Skull from above. For comparison with test-fig. 2. 

 Lettering as before. 



wings of the parasphenoid do not bear condyles and do not unite 

 with the pro-otics, but extend upwards to unite by suture with 

 the sphenotics and internally with the alisphenoids ; the orbito- 

 sphenoids are paired and separate. Small paired basisphenoids 

 are present, narrowly separated and pi-ojecting upwards in front 

 of the pro-otics, which roof the myodome just as in Lepidosteus ; 

 sphenotics and epiotics are much as in Lepidosteus, but in 

 addition there are well-developed opisthotics, and above them on 



