228 
AUG. F. FOERSTE 
27. ELRODOCERAS GEN. NOV. 
Genotype: Crytoceras indianense Miller 
Conch Actinoceroid, cyrtoceraconic , at the base, relatively 
straight at later stages of growth. Siphuncle ventrad of the cen- 
ter of the conch. Segments of the siphuncle presenting moder- 
ately convex vertical outlines; general form barrel-shaped, the 
end flat, and in contact with the intervening part of the septa. 
Surface of the conch transversely striated or banded as in the 
banded orthoceracones included by Hyatt under Geisonoceras. 
The bands curve downward along the ventral side of the conch, 
indicating a shallow but distinct hyponomic sinus. 
Rhynchorthoceras Remele belongs to the Lituitidae, a family 
confined to the Ordovician. 
The name Elrodoceras is proposed in honor of Dr. Moses N. 
Elrod, an indefatigable collector long living at Hartsville, 
Indiana. 
28. ELRODOCERAS INDIANENSE (MILLER) 
PLATE XXXV, FIGS. lA, B; PLATE XXXVI, FIGS. lA, B; PLATE 
XXXVII, FIGS. 2, 3; PLATE XXXVIII, PIGS. 2, 3 
Crytoceras indianense Miller; 17th Ann. Rep. Dep. Geol. Nat. Res. 
Indiana, 1892 p. 698, pi. 18, figs. 1, 2 
Rhynchorthoceras dubium Hyatt; Proc. Amer. Phil. Soc., vol. 32, 
1894, p. 512 
St. Paul type . — Early stages cyrtoceraconic, later stages rela- 
tively straight. The lengthwise convex curvature along the 
lower end of the ventral side has a radius of about 40 mm., the 
corresponding concave curvature of the dorsal side being much 
less. The specimen includes 15 camerae, in addition to which a 
trace of a segment of the siphuncle is. seen at its base. Along 
the upper 9 or 10 camerae the ventral side of the conch is straight 
lengthwise. The sutures of the septa are directly transverse to 
the conch. The . siphuncle is well exposed within the upper 4 
camerae. Within the uppermost camera, its maximum diameter 
is 23 mm., narrowing to 19 mm. at the septa. The septa wedge 
in between the successive barrel-shaped segments, the central 
passage through the septa being 12 mm. in diameter. At the 
septa, the siphuncle is 12 mm. distant from the ventral wall of 
the conch, and about 23 mm. from its dorsal wall, the entire 
diameter being estimated at 54 mm. 
The uppermost segment of the siphuncle exposes a cast of its 
interior ; the latter is marked vertically, both above and below an 
irregular transverse line which crosses the cast not far above 
