302 
LPI AL 
as KD) 
pon 
i 
15. 
PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXIV. 
PEATE, XOX. 
Deltopecten clathratus Lea. ; 
The typical specimen X 2. These two shells possibly belong together. 
That to the right, which is clearly a right valve, shows the charac- 
teristic hinge structure of Deltopecten. 
Myalina wyomingensis Lea. 
. The type-specimen, freed from the matrix by which it was _ artially 
concealed in the original figure. 
. The type-specimen of Lea’s Modiola minor. The original, which is an 
external mold, crushed and imperfect, is probably a young example 
of Myalina wyomingensis. 
Pleurotomaria? distans Lea. 
. The type-specimen X 2. A mere fragment, probably of a gastropod, 
though originally placed with the pelecypods. 
Hdmondia? perstriato Lea. 
. The type-specimen X 2. A mere fragment, probably the anterior end 
of a pelecypod. 
Pennsylvanian, Wilkes-Barre, Pennsylvania. 
Harttina indianensis, new species. 
. A specimen with rather indistinct dorsal sinus; ventral view. 
. Dorsal view. : 
. Dorsal view of a specimen with distinet dorsal sinus. 
. Ventral view of same. } 
. An ovate specimen with imperfectly developed sinus; ventral view. 
. Dorsal view. 
. Ventral view of a broad variety with distinct dorsal sinus. 
. Dorsal view. 
Specimen with the posterior portion ground down to show the internal 
structures. The ventral valve is seen to have two strong dental 
plates. In the dorsal valve the section passes below (interior to) the 
short low medium septum X 3. 
Another specimen similarly prepared X 38. The dorsal valve is seen to 
have a single septal plate, neither very long nor very high, without 
any trace of the lateral septa and platform characteristic of Diel- 
asma, The section touches the apex of the ventral valve and shows 
the beginnings of the dental plates. 
St. Louis group, Marion County, Iowa. 
GAD E Sexe 
Tegulifera armata, new species. 
. Dorsal view of a small specimen retaining both valves in place X 2. 
. Ventral view X 2. 
. Anterior view of ventral valve of a specimen with apertural spines and 
basal ridges X 2. 
Posterior view of same X 2. 
. Same, seen from below. 
