294 ANNALS OF THE CARNEGIE MUSEUM. 
lamina of inner gills free from abdominal sac. The mantle-connection 
separating anal and supra-anal shorter than in Anodonta. 
Type A. ferussacianus (Lea). 
This is practically an Anodonta with concentric beak-sculpture. 
The general make-up of the shell is much like Anodonta, while the 
beak-sculpture is suggestive of the Alasmidonta-group, without being 
so heavy. 
Anodontoides ferussacianus (Lea). 
Numerous specimens of the typical form, as well as of the var. 
subcylindraceus (Lea) have been investigated, the former from the 
Ohio drainage in western Pennsylvania, and the Cumberland River in 
Kentucky, the latter from Lake Erie. 
Bradytictic. The breeding season begins in August and ends in 
May; discharging specimens were found on May 14. 
Soft parts described by Lea (Obs., X, 1863, pp..449 and 451), and 
Simpson (in Baker, 1898, p. 73), but the latter is mistaken with 
reference to the marsupium of ferussacianus, while the description 
of that of subcylindraceus (p. 74) is correct. 
Anatomy essentially that of Anodonta, but it should be mentioned 
that the mantle-connection between anal and supra-anal is only about 
as long as the anal as well as the supra-anal. The inner edge of the 
anal is finely, but distinctly papillose. The posterior margins of the 
palpi are only connected for a short distance, and the anterior end of 
the inner gill is about half-way between that of the outer gills and the 
palpi. The marsupium has the same structure as in Anodonta, and 
the glochidia (Ortmann, 19110, pl. 89, fig. 12) are rather small for the 
subfamily, subtriangular, and about as long as high (0.32 mm.). 
They have hooks, although Lea (Obs., VI, 1858, pl. 5, fig. 35) figures 
and describes them as without hooks. 
I find that by a singular oversight I failed to make any field-notes 
on the color of the soft parts of this species but from alcoholic material 
and according to my recollection it is grayish white with the foot and 
the gills inclining to brownish. The marsupium containing glochidia 
is brown. 
Genus ALASMIDONTA Say. (1818.) 
(Simpson, 1900), p. 666.) 
Shell elliptical, or generally rhomboidal, inflated, with a well- 
developed posterior ridge. Disk generally smooth, but sometimes 
