PLATE 2-4. 



Page. 



Pig. 1. Ammonites complexus 447 



l,a. A side view of a small specimen, consisting entirely of septate volutions. 



1, b. An outline peripheral and aperture view of same. 

 l,e. A septum of same, magnified. 



Fig. 2. Placenticeuas placenta' 465 



2, a. A side view of a small specimen, consisting of the iuner septate volutions. 



2, 6. Another view of same, showing the very narrowly truncated periphery, the sagittate form 



of the aperture as indicated by a section of one of the inner volutions, and the sur- 

 face of a septum, with its numerous lobes. 

 Fig. 3. Pii yllocek as ? Halli _ 458 



3, a. A side view of the type-specimen, which retains a part of the distorted outer volutiou. 

 3, b. A peripheral view of the same, with the outer volutiou too much distorted by pressure 



to show the form of the aperture accurately by its section. 

 3, c. A septum of the same, magnified to about one aud a half diameters 



