352 Annals of the Carnegie Museum. 



Glochidia (Lea, Obs., VI, 1858, pi. 5, fig. 13, as occidens, and Ort- 

 mann, 191 lb, pi. 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, pi. 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, pi. 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- 



