CEPHALOPODA— ORTHOCHOANITES. 



99 



Fig. 1322a. Metacoce- • FiG. \-^2.2b. Metacoceras walcotti, X /^- (After 

 ras walcotti, end view, X Hyatt, Texas Survey, II.) 

 y^. (After Hyatt, Texas 

 Survey, II.) 



Strongly concave ; ventrolateral angulation with elongated nodes ; 

 venter rounded ; siphuncle ventral of center ; impressed zone mod- 

 erate. (Type of genus.) 



Coal Measures of Illinois, Missouri, Kansas, etc. 



123. M. cavatiforme Hyatt. (Fig. 1223.) Carbonic. 



Whorls broader and more quadrate than preceding; angle 



Fig. 1323. Metacoceras cavatiforme^ fragment showing internal whorls, X Vz- 

 (After Hyatt.) 



