180 ANNALS OF THE CARNEGIE MUSEUM. 
I call my specimens nebulosa with the distinct understanding, that 
one of them should rather be called iris. If it should prove to be 
correct, that nebulosa and iris are the same, nebulosa should be 
stricken off the list of the Cumberlandian types (Ortmann, 1924, 
p. 42). It is a species of very wide distribution, going northward as 
far as the Lake-basin, and exclusively represented in the upper Ohio 
drainage by the color-phase of zris. 
*53. Micromya lienosa (Conrad): R; D. 
Shells reported by Price as Lampsilis lienosus*®, L. caliginosus 
Conrad, and L. nigerrimus Lea probably belong here. Walker gives 
lienosa from Mammoth Cave and Bowling Green. At both these places 
I only collected the next species (ortmanni). In addition, Walker 
has M. vanuxemensis (Lea) from Gasper Creek and from Rio. Sketches 
of the latter specimens (Rio), submitted to me, show, however, that 
they resemble /ienosa, since according to Walker they have purplish 
or white nacre, and not the peculiar salmon-tint of ortmanni. I did 
not see specimens of /ienosa among the material from Rio collected 
by Clench in 1925. But there are seven specimens from Dunnville, 
three males, four females according to shape. These distinctly differ 
from ortmannt. The shell is not so thick, the epidermis is blackish 
brown, rays are hardly present (only barely indicated in some). The 
nacre is whitish, with no salmon-color whatever, but in some specimens 
with purplish tints posteriorly. The constriction of the female shell 
is absent, or there is only a faint trace of it. These specimens corre- 
spond to the white-nacred phase of lienosa, often called nigerrima 
Lea, as found in the western and northern extension of the range 
from Louisiana and Arkansas into Illinois and Indiana. 
*54. Micromya ortmanni Walker: Mm; O; Mf; R; B. 
Also in Sulphur Fork of Russell Creek, Adair Co., Walker. 
The type-locality is Mammoth Cave (Walker, 1925, p. 1), and I 
have a dead female from this place. Very likely this new species has 
also been collected by Price, and the form mentioned as L. vanuxe- 
mensts Lea is this; but some of the names quoted above under lienosa 
may also belong here. 
®» L. lienosus stands in Price’s list on the same line with L. luteolus: in analogy 
to Tritigonia verrucosa Rafinesque and U. tuberculatus Barnes, this might be taken 
for an indication of their synonymy. But this would be preposterous. 
