ON THE OSTEOLOGY OF NYCTOSAURUS 163 
described and partly figured without certain errors into which he has 
fallen, and that the peculiar “‘spiral’’ condyles of both Pteranodon and 
WVyctodactylus have likewise been describéd and figured, without, however, 
their having suggested to any one the probability that the animals dis- 
located their jaws in deglutition. 
