539 
species of Martinia from the Iberger Kalk, Upper Devonian of Grund, 
Germany, with which he considered the species to be closely related. 
Liphippioceras. 
EPHIPPIOCERAS FERRATUM, Hyatt. 
NAUTILUS FERRATUM, Owen (Geol. Kentucky, iii, Pl. x, Fig. 2). 
Figs. 23-26, Pl. x, enlarged 5 diameters. 
The nepionic stage is given in Fig. 23, from the side showing the 
lateral longitudinal ridges of the paranepionic and part of the meta- 
nepionic substage. These ridges are more acute on the venter and 
wider apart and blunter on the sides. ‘The form in section of the 
metanepionic is digonal, and that of the paranepionic substage has 
amore elevated venter and flatter dorsum. ‘There was no dorsal 
furrow in the paranepionic substage, so far as could be ascertained, 
but the condition of the specimen left this fact open to doubt. 
It is interesting to note that the form and characters of the young 
of this very aberrant form seem to indicate affinity with the Eudo- 
ceratide. ; 
The peculiar ridge-like mesal division of the septa, which corre- 
late with the prominent ventral and dorsal saddles of this genus, are 
not present in the nepionic stage. The imperfect condition of this 
fossil did not enable me to make detailed observations upon the 
young farther than in the stage figured. 
Trigonoceratide. 
This family includes the close-coiled nautilian forms Coelonau- 
tilus, Stroboceras, Apheleceras, Subclymenia and Diorugoceras. 
The young of all of these genera, except possibly Diorugoceras, 
which I have not seen and which is also very involute, have a simi- 
lar history. They are rounded in the nepionic stage and have an 
impressed zone only late in life, if they have it at all. Usually the 
form is similar to that given in Figs. 29 and 30, Pl. x, of Apheleceras 
mutabile (sp. D’Orb.), Hyatt. 
This species shows in the young that the genus has been but 
recently derived from an arcuate type. The apex in the ananepi- 
onic and part of the metanepionic substage is free and the whorls 
barely touch at first. The corrugated shell of the nepionic and 
neanic stages show also the same primitive characters and the resem- 
blances of these younger stages to the loosely coiled gyroceran form 
