598 
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 “ndolobus avonensis, Fig. 38, 
Pl. 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, Pl. 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. (?) 
Plexi, Hig. 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, N. Ss. 
Loc., Faxoe, Denmark, Cretaceous. 
Peace Pigs -o—12. 
This species differs from Hudtrephoceras Dekayi in the extreme 
subdorsan 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 4. De- 
kayt. ‘The development is, however, so similar otherwise that no 
