444 
slightly convex and slope evenly and divergently outwards and con- 
sequently appear flattened in some specimens. 
The envelopment covers the abdomen, which last is prominently 
convex. 
The length of the sub-V-shaped dorsal lobe in the sutures is 
greater than in any species I have yet seen, and this is very instruc- 
tive. Occurring as it does in a shell which is not very involute, 
and with a contact furrow but little exceeding the ordinary 
dimensions, it shows that the depth of the dorsal lobe in the 
sutures is not only correlated with the extent ‘and depth of the 
contact furrow but also largely dependent upon the concavity of the 
septa. In other words, if this species had had septa of ordinary 
concavity the dorsal lobes in the sutures would not have been so 
deep and sub-V-shaped as they are. The sutures have also broad 
lateral lobes running well forward to sharp saddles at the lines of 
involution. There are broad saddles at the abdominal angles and 
shallow ventral lobes or straight sutures across the venter. The 
siphuncle becomes intracentroventran in the ephebic stage and is 
very large, as it is in Lurystomites Kellogg?. ‘The whorls come in 
contact in the ananeanic substage. The shell grows quite large, 
but, so far as I have seen, none have any part of the last whorl free. 
EURYSTOMITES VIRGINIANA. 
NavuTILUS KELLoGGI(?) (gars), Whitf. (not figured). 
Loc., near Lexington, Va., and Fort Cassin. 
This shell had more cylindrical whorls and more numerous and 
straighter sutures at all stages than in Aec//ogg?. ‘The siphuncle is 
nearer the venter, and in the type-specimen, which is over 90 mm. 
in diameter (in collection U.S. National Museum), it is still almost 
subventran at the entrance into the living chamber. This last is 
less than one-half of a volution in length. ‘The whorl is almost 
circular in this specimen at all stages observed, including the neanic 
stage, and the involution is very slight; the dorsal lobe correlates 
’ with this, being correspondingly shallow and narrow. ‘The sutures 
otherwise resemble those of Aed//ogg?, but are straighter, and the 
three specimens from Virginia do not show the ventral lobes that 
often occur in Kedlloget. 
There is a young: specimen in the American Museum under the 
name of Ke//oggt, from Fort Cassin, that appears to belong to this 
species, having similar sutures, form of whorl and involution. 
