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others it may still remain nearer the dorsum, but in most shells it 

 shifts its position somewhat. 



In the metephebic stage the shell appears to have been smooth 

 and the whorl is apparently somewhat more depressed or more 

 absolutely nephritic in outline. This distinction is due to the 

 larger size and greater proportionate increase in lateral growth. 

 The dorsal sutures in this substage and probably throughout the 

 ephebic and possibly earlier have not only the broad dorsal lobes 

 in the contact furrow, but narrow and very shallow lobes, which 

 cannot be described as annular lobes, although they resemble these 

 as they appear in the neanic stage of Endolobits avonensis, Fig. 38, 

 PI. viii. They are, however, much shallower. In the centre of 

 these, in the only specimen perfect enough to show this, there were 

 minute linguiform saddles as given in Fig. 1, PI. xiv. The sutures 

 have to be in perfect condition to observe such markings and this 

 may account for the absence of similar markings upon other nauti- 

 loids. The siphuncle may be either ventrocentren, centren or 

 dorsocentren, but it is more commonly dorsocentren. 



EUTREPHOCERAS, Sp. (?) 



PL xiii, Fig. 3. 



Loc, France, Cretaceous. 



This shell is referred to here because it shows clearly the pres- 

 ence of a faint dorsal furrow in the metanepionic substage opposite 

 a corresponding furrow in the paranepionic. The cast of the per- 

 foration was preserved in this specimen and it was extremely flat 

 and comma shaped. The whorls are coiling towards the observer 

 so that there can be no doubt that the section of the central volu- 

 tion is metanepionic. 



EUTREPHOCERAS FAXOENSE, 11. S. 



Loc, Faxoe, Denmark, Cretaceous. 

 PL xiii, Figs. 9-12. 



This species differs from Euirephoceras DeJzayi in the extreme 

 subdorsal! position and smaller size of the siphuncle in the nepionic 

 stage, has larger umbilical openings and is also apparently a smaller 

 form. Otherwise it is very close in sutures and form to this spe- 

 cies. The umbilical cast is preserved on one side in Fig. 9, and 

 shows the involution to have been considerably less than in E. JDe- 

 kayi. The development is, however, so similar otherwise that no 



