346 



Annals of the Carnegie Museum. 



generally with a black streak, and often has a peculiar eye-spot at 

 the posterior end, close to the branchial. In the male a similar struc- 

 ture is found in a rudimentary condition. 



Marsupium kidney-shaped, swollen, formed by many ovisacs, 

 occupying the posterior part of the outer gill. Edge of marsupium 

 blunt, beaded, generally pigmented. Placentae not solid. Glochidia 

 subovate, rather large. 



Type L. ovata (Say). 



In the specialization of the edge of the mantle in front of the 

 branchial this genus represents the highest type of Lawipsiliniz. 



Lampsilis anodontoides (Lea). 

 I have one male and two gravid females from the Colorado and Rio 

 Grande Rivers in Texas (D. A. Atkinson coll. May, 1907); five speci- 

 mens (males and females) from Kansas River, Lawrence, Douglas 

 Co., Kansas (R. L. Moodie); one young male and one gravid female 

 from Ouachita River, Arkadelphia, Clark Co., Arkansas (H. E. 

 Wheeler, coll. Feb. 6, 191 1). 



mp 



Fig. 25. Lampsilis anodontoides (Lea). Gravid female, from Rio Grande, 

 Mercedes, Hidalgo Co., Tex. (Cam. Mus., No. 61, 2,155.) 



The gravid females all have glochidia, and show that the species 

 is bradytictic, carrying the larvae over the winter. 



The soft parts have been described by Lea (Obs., X, 1863, p. 406) 

 and Simpson (in Baker, 1898, p. 101). 



Mantle-connection between anal and supra-anal of medium length, 

 shorter than the anal. Anal crenulated, branchial with papillae. 

 In front of the branchial the inner edge is in the female lamellar and 

 dilated, forming a ribbon-like expansion, which is (in alcoholic speci- 



