CLASS V 



CEPHALOPODA 



667 



Eurynoticeras Canavari. Jura. Desmoceras Zittel (Fig8. 1296, 1297); Puzosia 



Eayle ; Ghonoceras Paroiii and 

 ^ Bon. ; Scldueteria, Hauericeras 



^V^ <^V"^? ^ Grossouvre. Cretaceous. 



Subfamily B. Silesitinae 

 Hyatt. 



Similar to. the Desmoceratinae, 

 but costae more strongly de- 

 veloijed, and sometimes spinous. 



Fio. 1297. 



Desmoceras mayorianura (d'Orb.). Gault ; Perte du Rhcjne 

 (after d'Orbigiiy). 



Fio. ]298. 

 Pachydiscus iieranvplus (Maiitell). Lower Chalk ; England. 



Fig. 1299. 



Pwhyiliscus loittcldmli (Scliliiter). 

 Upper Cretaceous ; Haldem, Wost- 

 pVialia. Vs- 



Silesites, Holcodiscus Ulilig ; PacJiy discus Zittel (Figs. 1298, 1299); Parapachy- 

 discus Hyatt. Type P. {Ammonites) gollevillensis (d'Orb.). Cretaceous. 



Family 28. Cosmoceratidae Zittel. 



Shells richly ornamented tvith ribs that are divided, or broken uf into rows of knots. 

 Usually with rows of umbilical and marginal knots on the ribs. Sculpture interrupted 

 by a furrow on the venter. Aperture often with lateral ears or lappets. •! Septa deeply 

 digitate. One or tivo auxiliary lobes present. 



