ISOTELUS, ACROLICHAS, CALYMENE, AND ENCRINURUS 77 
Calymene sp. (West Union form) 
Plate XVIII y figs. 8 B 
The type of Calymene vogdesi Foerste (Bull. Sci. Lab. Denison 
Univ., 2, 1887, p. 95, pi. 8, figs. 12, 16) is a large cranidium with 
a broad, massive border, separated from the anterior part of the 
glabella by a broad groove. The glabella is long, the dorsal 
furrows are not strongly convergent, and the anterior margin of 
the glabella has a broadly rounded outline. The accompanying 
pygidia have five pairs of ribs. All ribs, except those belonging 
to the last pair, are grooved for a short distance from the dorsal 
furrow, and for a longer distance from the distal end of the rib. 
Along the intermediate part of the ribs, the furrow is very faint or 
entirely obsolete. This species is characteristic of the Brass- 
field formation. 
In the Holophragma zone at the top of the West Union forma- 
tion at Hillsboro, Ohio, a much smaller species of Calymene 
occurs, (Ohio Jour. Sci., XIX, 1919, p. 402, pi. 18, fig. 6) about 
three-fifths as large as typical Calymene vogdesi. It has about 
the same form of cranidium, but the anterior half of the glabella 
is more quadrangular and is truncately rounded anteriorly; the 
anterior margin of the cranidium is relatively broad, but there is 
no broad groove separating this border from the anterior margin 
of the glabella, as in Calymene vogdesi. 
In the Trimerus (formerly referred to Homalonotus) delphino- 
cephalus zone, about 10 feet above the base of the West Union 
formation, at the quarry in the southeastern corner of West 
Union, Ohio, cranidia (figs. 8 A, B, on plate XVIII of this Bulle- 
tin) were found which closely resemble those from the Holo- 
phragma zone mentioned above. They differ chiefly in having 
a narrower anterior border, which bends more strongly upward, 
so that, from above, this border appear's more narrow than its 
actual width. The accompanying pygidia show five pairs of 
ribs, the grooving of which can not be determined from the 
specimens at hand. 
