CEPHALOPODA. 05 



16. Cassiani, 36 sp. of very variable form, and remarkable for the number 

 and complexity of their lobes. Trias, Austrian Alps. 



T^ nl 



A 3 



Fig. 57.* 



Ex., A. Maximiliani (fig. 57), A, Metternichii. 

 CRIOCERAS, Leveille. 



Etym., krios, a ram, and ceras, a horn. 



Syn., tropseum, Sby. 



Ex., C. cristatum, D'Orb. (pi. III., fig. 8). 



Shell, discoidal ; whirls separate, 



Distr., 9 sp. Neocomian Gault ; Brit., France. 

 TOXOCERAS, D'Orb. 



Etym., toxon, a bow, ceras, a horn. 



Ex., T. annulare, D'Orb. (pi. III., fig. 12.) 



Shell, bow-shaped ; like an ammonite uncoiled. 



Distr., 19 sp. Neocomian. Between this and crioceras and ancylo ceras 

 there are numerous intermediate forms. 



ANCYLOCERAS, D'Orb. 



Etym., anculos, incurved. 



Ex.* A. spinigerum (pi. III., fig. 10). 



Shell, at first discoidal, with separate whirls ; afterwards produced at a 

 tangent and bent back again, like a hook or crosier. 



Distr., 38 sp. Inf. oolite chalk. S. America (Chile and Bogota), Europe. 

 SCAPHITES, Parkinson. 



Etym., scaphe, a boat. 



Ex., S. equalis (pi. III., fig. 9). 



Shell, at first discoidal, with close whirls ; last chamber detached and 

 recurved. 



Distr., 17 sp. Neocomian chalk. Europe. 

 HELICOCERAS, D'Oub. 



Etym., helix (helicos), a spiral, and ceras, horn. 



Ex., H. rotundum, Sby, sp. pi. III., fig. 11 (diagram). 



Fig. 57. Am. Maximiliani Klipstein. (= A. bicarinatus Miinst). Trias, Hall- 

 stadt (copied from Quenstedt). A, Profile shewing the numerous lobes and saddles. 

 B, suture of one side; v, dorsal saddle. 



