164 (^iticiiiHaii Society of Natural History. 



DESCRIPTION OF SOME SUBCARBONIFEROUS AND 

 CARBONIFEROUS CEPHALOPODA. 



By S. a. Miller and Chari.ks Faher. 



(Presented January 5, 1892.) 



GONIATITES MISSOURIENSIS, 11. .sp. 



Plate 6, Fiii'. I, side tvVrr, natural size. 



Shell luediuni .size, .subglobose, rounded on the dorsum. 

 Umbilicus large, abrupt, deep and showing very little of the 

 inner whorls. Volutions few, increasing rather rapidly in 

 size, broadly rounded upon the sides of the inner whorls, but 

 more and more flattened laterally as the body chamber is ap- 

 proached ; transverse diameter of the inner whorls equal to 

 or greater than the width from the dorsal to the ventral side, 

 but near the aperture the dorso-veiitral diameter is twice as 

 great as the transverse. \'olutions profoundly grooved within 

 for the reception of the inner whorls. Our specimen reveals 

 only the septate portion, and hence the body chamber and 

 aperture are unknown. 



Septa close, fairly crowded and deeply sinuous. There are 

 three lobes and three saddles on each side. The saddles are 

 linguiform, being regularly rounded, at the ends, and the 

 superior ones being longer than the inferior ones or those 

 nearer the umbilicus. The lobes are lanceolate, as long as 

 the saddles, and sharply pointed at the e.Ktremities, which hug 

 closely the saddles on the superior side. Dorsal lobe and 

 saddle not determined. 



The general form, closely crow^ded septa, and direction of 

 the extremities of the lobes toward the superior saddles will 

 distinguish this species from all others. 



