443 
EURYSTOMITES ROTUNDUS. 
NauTiLus Kettocet, Whitf., of. cit. (Bull. Am. Mus., New York, 
pe Ih ence, eS. 54, 653) not: P).. xxx). 
Loc., Fort Cassin. 
Pl. v, Figs. 21-25. 
This species increases more rapidly in the growth of the ventro- 
dorsal diameters than in Ae//ogg7 and retains the siphuncle near the 
venter for a longer time during the growth. This may be due, 
however, to the differences in the size, and not a matter of age, 
since in large whorls it assumes a similar position to that of Ke//ogg7. 
Fig. 21, Pl. v, gives a view of the first two whorls from the side, 
partly restored from the study of the section, and the dotted lines 
explain the position of the last section (Fig. 25, Pl. v) of the 
centre of first volution. 
This figure shows the metanepionic above and paranepionic be- 
low, just before the paranepionic comes in contact with the apex. 
This was the last section taken. Fig. 22 shows the first section, 
secured through the inner dorsal part of the metanepionic substage, 
_and Figs. 23, 24, Pl. v, show the successive sections connecting 
this with Fig. 25, and thus demonstrating the large size of the 
umbilical perforation and the correlative rotundity of the dorsi of 
the meta- and paranepionic substages. 
EURYSTOMITES GIBBOSUM, N. g. 
Loc., Port au Port Choix, Schooner Taland, Newfoundland. 
I mention this new species here without giving figures, because it 
is important in the consideration of the relations of the dorsal lobe 
and impressed zone and it is so peculiar that it can be easily recog- 
nized. 
The general aspect is like that of Hurystomites Kelloget, but the 
septa are more deeply concave than in any species of these faunas 
and the lateral sutures run forward on the sides as in Tarphyceras. 
The outlines of the whorls in section at all epinepionic stages is like 
that of the last whorl of the specimen of Wautilus Kelloggt, here 
Lurystomites rotundus, as figured by Whitfield on PI. xxxi, Fig. 4a Aw Sa, 
and in section the whorls at all stages are ovals similar to the meta- 
nepionic substage of Lurystomites rotundus (Fig. 25, Pl. v), but 
the abdomen is rounder. No lateral zones or umbilical zones are 
differentiated, but there is a faint approximation to the digonal 
form probably in the early neanic substages. The sides are only 
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