352 ANNALS OF THE CARNEGIE MUSEUM. 
Glochidia (Lea, Obs., VI, 1858, pl. 5, fig. 13, as occidens, and Ort- 
mann, 1911, pl. 89, fig. 23): length 0.25; height 0.29 mm. 
Lampsilis excavata (Lea). 
Two males, Pearl River, Jackson, Hinds Co., Mississippi (A. A. 
Hinkley). 
Structure of soft parts as in the foregoing species. Since no females 
are at hand, the shape of the mantle-flap, the marsupium, and glochidia 
could not be ascertained, but the latter have been figured by Lea (Obs., 
XIII, 1874, pl. 21, fig. 6). My two males have a rudimentary mantle- 
flap, consisting of a narrow lamellar keel, with a black streak on the 
inside, ending anteriorly in a short, angular projection. This is similar 
to the males of L. ovata and ventricosa. The posterior margins of the 
palpi are united for from one-third to one-half of their length. 
This form undoubtedly falls into the same group with the foregoing 
species. 
Lampsilis multiradiata (Lea). 
Six males and six females (three gravid) are at hand, from the Ohio 
drainage of western Pennsylvania. 
Breeding season probably as in the preceding species; in fact I have 
found gravid females in May, June, July, August, September, and 
October. Discharging females were found as late as August 9. 
Females with eggs were secured in the beginning of September. 
Thus it seems that the seasons overlap later than in L. luteola and 
ventricosa, in August. : 
Soft parts (described by Lea, Obs., X, 1863, p. 426, and Simpson, 
in Baker, 1898, p. 96) absolutely identical with those of L. ovata and 
ventricosa, only there are a number of teeth along the edge of the flap. 
Colors also similar, but the orange on the margin of the mantle and 
flap prevalently very bright. Glochidia (Lea, Obs., VI, 1858, pl. 5, 
fig. 17): length 0.25; height 0.29 mm. 
Lampsilis cariosa (Say). 
Four males and four females (two gravid) from the Susquehanna 
and Delaware drainages in eastern Pennsylvania. Many more 
investigated in the field. 
The breeding season begins in the first half of August. In 1910, 
I was unable to find any gravid females on August 7, in the Susque- 
