8 



„ Tro cholites. 



„Involute; symmetrica! ; wtiirls contiguous; the back of 

 inner volutions rounded, Atting into a corresponding groove; 

 septa convex; siphuncle near the inner margin. 



„This genus differs from Lituites in having a submarginal 

 siphuncle, and in not being extended into a streight or bent 

 Prolongation. The aperture is widely different, being of a 

 lunate outline , whilst in Lituites it is nearly round. 



„Trocholites planorbiformis. PI. 17. Fig. 1. — Vo- 

 lutions higher than wide, longitudinally striated, and with oblique 

 obtuse, transverse lines, approaching at an angle but rounded 

 on the centre of the back; apex profoundly depressed; back of 

 the large volution flattened; aperture much longer than wide. 



„Locality. Near Grimsby, Upper Canada, in Salmon 

 river Sandstone. This elegant shell was found in a boulder, 

 by Mr. Ashmead of this city, and by him presented to the 

 Academy of Natural Sciences. A specimen was kindly given 

 me by this liberal and enterprizing mineralogist." 



Der grösseren Deutlichkeit halber sind nachstehend die 

 beiden Originalfiguren Conrad's in genauen Copien wieder- 

 gegeben. 



Figur 3 a. Figur 3 b. 



Fig. 3 a. Seitenansicht von Trocholites planorbiformis Conrad. 

 Fig. 3 b. Wahrscheinlich der Längsschnitt der Wohnkammer eines 

 grösseren Exemplars (Erläuterungen hat der Autor diesen Figuren nicht 

 beigefügt). 



