5C6 
ures or lobes to correspond with the ventral channels, but these 
were very indistinct through the shell. 
The siphuncle is of medium size and ventro-centren in the 
middle of the volution actually seen, and at its termination in what 
seemed to be the septal floor it was centren. 
The original specimen is a nearly completed whorl, 36 or 37 mm. 
in diameter, and if prolonged and restored to a point opposite the 
dorsal marks described above it must have been, when complete, 
about 74 or 75 mm. in diameter. 
The dark blue color of the last septum of the fragment described 
indicated that it might have been the floor of the living chamber, 
and if so, that hving chamber must have been over three-quarters 
of a volution in length. Every observer, however, knows that this 
inference is open to great doubt because of the frequent invasion 
of the matrix into septal chambers through accidental breaks in the 
shells. Pseudo-septa were observed in this specimen. So far as 
could be seen the involution simply covered the abdomen, and the 
contact furrow, although not perceptible on the first part of the 
whorl described, was evidently present later. ‘This is very inter- 
esting, because this furrow is not persistent upon the uncoiled 
whorls in any species or form of Lituites yet described and seems 
to have no hold at all upon the organization. 
Lituttes. 
This generic name has been applied to the majority of forms that 
have the last part of the last whorl or the living chamber free. 
This general application of the name is so erroneous that it hardly 
needs discussion. It is, as stated above in this paper, a common 
tendency of the growth of the whorls in degenerative shells of the 
Nautiloids throughout the Paleozoic and of the similar forms of 
Ammonoids during each geologic period, and also a common ten- 
dency of the extreme senile or paragerontic substage in the ontogeny 
of all shells of both orders whenever they attain the extreme limits 
of their existence. Later authors, especially Remelé, Ndtling, 
Dewitz and Holm, have recognized this fact in some way, either 
directly or by limiting the generic application of the name Lituites, 
or by separating the genera Ancistroceras, etc., from Lituites. 
Remelé was the first to demonstrate the divisibility of the Lituitide 
into different genera, Boll’s previous effort in this direction being 
unsystematic and subsequently repudiated by himself. 
