CEPHALOPODA— ORTHOCHOANITES. 



77 



with a row of large nodes at ventrolateral angles. Siphuncle small 

 and tubular. Siluric-Devonic. 



84. H. (?) hercules Winchell and Marcy. (Fig. 1292.) Siluric. 



Large, gyroceraconic, making one entire volution or more; 



whorls smooth, not in contact, rapidly expanding; outer portion 



Fig. 1 29 1. Zitteloceras hallia- FiG. 1 292. Halloceras (/) hercules, lateral 



num, lateral view of a fragment, view and septum, of a specimen denuded of the 

 (After Clarke, Pal. Minn.) shell, X I- (After Hall, 20th Mus. Rep.) 



less arcuate. Section broadly elliptical, a little flattened on sides 

 and wider ventrally than dorsally ; siphuncles small, centren or sub- 

 centren; aperture with hyponomic sinus; septa rather distant. 

 Niagaran of Wisconsin and Indiana. 



85. H. undulatum (Vanuxem). (Fig. 1293.) Devonic. 

 Whorls two to three, not in contact; section subtriangularly 



ovate; septa distant; nodes faint. 

 Onondaga of New York. 



86. H. paucinodum Hall. (Fig. 1294.) Devonic. 

 Closer coiled than preceding; section more triangular; nodes 



strong, distant, and elongate transversely. 

 Onondaga of New York. 



