Preliminary Notes on Cincinnatian Fossils 221 
the conclusion that Miller probably had specimens of Dalmanella 
jugosa at hand when he described Orthis meekly but this is ren- 
dered uncertain by his assigning the species to the Fairmount 
horizon, and by the fact that three collectors from, the same town 
within 4 years of the first description of this species actually 
referred Orthis meeki to Orthis emaceratay which would be the 
natural affiliation of the Fairmount species. However, no matter 
what Miller intended to do, his republication of Meek’s descrip- 
tion of Orthis emacerata and his reference to figs. 2 a to 2g as illus- 
trations of typical specimens, would make Meek’s types also the 
types of Orthis meeki. Meek’s types can not be found. How- 
ever, as long as no careful search has been made in the top of the 
Eden formation, or in the overlying strata, including the Fair- 
mount, for large Dalmanellas which might have been used as a 
basis for Meek’s description, and possibly also for his figures, the 
use of this term must remain uncertain. Large specimens of 
Dalmanella sent to me several years ago by Mr. John M. Nickles, 
and labeled as coming from the upper Eden, suggest that such 
forms may exist. Hence, for the present, the term Dalmanella 
jugosa seems preferable, until the identity of the specimens de- 
' scribed by Meek has been established beyond all question. 
Dalmanella (Bathycoelia) bellula, Meek. 
Dalmanella bellula belongs to the group of Dalmanellasy typified 
by Dalmanella subcsquatay Conrad, in which the brachial valve 
is strongly convex, and the median depression is absent or only 
faintly indicated. This group appears to have had a phylogenetic 
history distinct from the group typified by Dalmanella testudinaria. 
It ranges from the Stones river to the Devonian. For the species 
included in this group, the term Bathycoelia is proposed as a sub- 
j generic term. 
1 Plectorthis fissicosta, Hall. 
I {Plate IV, Figs. 5 A, B.) 
! The illustrations of the type specimen of Orthis jis si costa y pre- 
I served in the American Museum of Natural History, as presented 
I in fig. 7, on plate 32 of volume i of the Paleontology of New Tork, 
is not sufficiently definite for present needs of paleontological 
study. For this reason, photoengraved illustrations, one of them 
