PLATE XXXVII 
Fig’. 1. Monocyrtoceras lentidilatatum Foerste. Lateral view, ex- 
posing one segment of the siphuncle at the base. See also Plates XXXVIII, 
fig. 1; XXXIX, fig. 1; XL, figs. 1 A, B ; and XLI, figs. 3 A, B. From Green- 
field, Wisconsin, in the Racine member of the Niagaran, Specimen No. 2315 
in the Museum of Comparative Zoology, at Harvard University. 
Fig. 2. Elrodoceras indianense (Miller). Ventral side, retaining the 
transverse surface striae. From Hartsville, Indiana, in the Laurel mem- 
ber of the Niagaran. Same specimen as that figured by Miller, in 17th Ann. 
Rep. Dep. Geol. Nat. Res. Indiana, 1892, pi. 18, fig. 2. 
Fig. 3. Elrodoceras cf. mdianense (Miller). Natural section, exposing 
the siphuncle. From Lemont, Illinois, in the Niagaran. Specimen No. 
22917, in the Museum of Comparative Zoology, at Harvard University. 
See also Plate XXXVHI, fig. 2. 
