CEPHALOPODA— AMMONOIDEA. 



179 



the aperture; ribs of adult bifurcating and trifurcating; nodes only 

 on last half, those of inner row nearly obsolete. 



Lower Ripleyan of New Jersey ; common. > 



CXXXII. Baculites Lamarck. 



Straight shells except for the minute apical portion which is 

 enrolled, but generally lost; section varying from elliptical or oval 

 to ovoid, generally sharper on posterior side ; living chamber large, 

 with anterior ventral prolongation, generally indicated by the 

 smooth lines ; suture comparatively simple ; surface smooth. 

 Cretacic. 

 300. B. gracilis Shumard. (Fig. 1432.) Cretacic. 



Small, slender, scarcely tapering; broad ovate to subelliptical in 



Fig. 1432. Baculites Fig. 1433. Bacu- 



^rf'ad/is,\^, w\ih sec- lites chicoensis, with 



tion and suture. (After section. ( After Gabb.) 

 Stanton.) 



Fig. 1434. Bactdites chicoensisy 

 suture enlarged. (After Gabb.) 



