OrnitJiosauri'an Genvs Ornitlioclieirns. 557 



apportioned to any particular genus, except those which, by 

 comparison with the American formSj belong to Ornitho- 

 stoma. 



The other groups must remain isolated until some further 

 discovery determines their relationship. 



Classification. 



Family Ornithocheiridae. 



Subfamily Ornitrocseirinm. 



Genera Ornithocheirus (Seeley). 



LONCHODECTES. 



Subfamily Criorkyncsin^. 



Genera Criorhynchus (Owen). 

 Amblydectes. 



Family Ornithostomatidae. 



Genus Orxithostoma (Seeley). 

 (Pteranodon, Marsh.) 



In conclusion, I would like to bear witness to the magnifi- 

 cent work of Seeley in the determination and interpretation 

 of such fragmentary material. It must have been a most 

 diificult task. I also desire to thank Professor T. McKenny 

 Hughes for his courtesy and kindness in lending me the 

 type-specimens for study. 



EXPLANATION OF PLATE XXII. 



Fiff. 1. Left lateral view of Cambridge specimen J. c. 9. O., orbit; 



•SV.OC'.C'i?., supra-occipital crest ; OC, occiput. X about 4. 

 Fiff. 2. Occiput of same specimen above the foramen mag-num. /.?»., 



foramen magnum ; p.t.f., post-temporal fc ssai. X about ^. 

 Fig. 3. Posterior view of skull of same specimen, Su.OC.CR., section of 



supra-occipital crest ; OC, occiput, x about |. 

 Fig. 4. Left lateral view of the tip of the upper jaw of Criorhynchus 



simus (after Owen). Nat. size. 

 Fig. 5. LeI't lateml view of a portion of the upper jaw of Colohorhynchus 



clnvirostris (after Owenj. The dotted lines indicate the amount 



of the upper jaw worn away by attrition. Nat. size. 



