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Figs. 23 and 24. Trocholites canadensis, Hyatt; Loc, Falls of Montmo- 

 rency (?); Coll. Mus. Comp. Zoology, Bronn Coll. 



Fig. 23. Much enlarged. The siphuncle shows through the transparent venter 

 of the nepionic volution and it passes from subdorsan in the paranepionic below 

 to centren in the metanepionic above. The umbilical perforation appears beyond 

 the siphuncle and has a well-developed dorsal furrow, can also be seen ; Fig. 24 

 shows the gibbous outgrowth of the dorsum in the umbilical perforation at some 

 distance from the gyroceran bend. 



Fig. 25. Trocholites (Lituites) intemastriata (sp. Whitfield), Hyatt. This 

 was drawn from the centre of his original specimen, Bull. Am. Mus. Nat. Hist. 

 A r . K, PI. xxix, Fig. 6, enlarged to show the centren position of the siphuncle in 

 the first septum and its gradual approach to the dorsum in the paranepionic whorl 

 as in T. canadensis. This also shows a much larger umbilical perforation than 

 is found in Canadensis or ammonius or the species figured by Holm. 



Fig. 26. Trocholites sp. ? after Holm, Pal. Abh. Dames et Kayser, iii, PI. v, 

 Fig. 11, to show the probable beginning of the siphuncle to be nearer the centre 

 than is described by him. His Fig. 9 of Trocholites incongrtius shows also a 

 small umbilical perforation and the siphuncle subdorsan, but its tip or caecum is 

 directed towards the centre of the apical chamber. 



