PLATE 14. 



Fig. 1. 88. 1. GoNiocERAS anceps. (Pag. 54.) 



1. Natural longitudinal section of a Gonioceras, showing a portion of the siphuncle, which is greatly expanded 

 laterally between the septa, and contracted at their junction with it. In this specimen, the sides are 

 worn down below the angles of the shell ; so that the septa do not appear to turn backwards or towards 

 the apex, as shown in 1 o, where the section is more directly through the angles. 



1 a. A longitudinal section, showing a small portion of the siphuncle at one extremity, and a more perfect 

 exhibition of the curving septa towards the exterior of the fossil. 



1 4. A transverse section, showing the position of the siphuncle. The specimen, on the upper side of the figure, 

 has been slightly worn, so as to present a straight line. The siphuncle is nearer to the upper edge than 

 is represented in the figure. 



1 c. A transverse section near the smaller extremity of the shell, showing the position of the siphuncle. 



1 d. A small portion of the exterior denuded of the shell, showing only the central portion of the septa. 



