Ortmann: Families and Genera of Naja :;it 



niti^) either merely suddenly truncated in front, or forms a small 

 free lube, variable in my more or less contracted specimens. Along 

 its edge this expansion is crenulated, but has no papilla 1 , and the whole 

 inner side of this flap is of a brownish black, color, sometimes a distinctly 

 brown streak between two black streaks is seen. No eye-spot has been 

 observed. The flap extends over about one-third of the lower margin, 

 and farther in front the inner edge of the mantle is smooth. 



Posterior margins of palpi connected for about one-fourth of their 

 length. Gills and diaphragm of usual shape and structure. Inner 

 lamina of inner gills connected with abdominal sac. 



Marsupium kidney-shaped, occupying about the posterior half of 

 the outer gill, composed of numerous (about thirty) ovisacs. Margin 

 of marsupium with blackish pigment. A very small section of the 

 gill posteriorly is non-marsupial. Glochidia (Lea, Obs., VI, 1858, 

 pi. 5, fig. 2) rather large, subovate. Length 0.20; height 0.26 mm. 

 (see Plate XX, fig. 9). 



Color of soft parts whitish, with little brown on the edge of the 

 mantle, and the markings on the flap and the marsupium as described 

 above. 



According to the shape of the shell, this species was always sup- 

 posed to be closely related to Eurynia recta, but I doubt whether there 

 is actually a close relationship between these two species. The 

 mantle-flap of L. anodontoides is entirely different from the papillae 

 of E. recta. However, in L. anodontoides the mantle-flap has not yet 

 attained the typical development of the genus, and the anterior free 

 end is in particular rather indistinct. Probably it is the most primi- 

 tive form of Lampsilis and connects this genus with more Eurynia- 

 like ancestors, but it cannot be placed in Eurynia on account of the 

 lack of papillae on the edge of the mantle. 



Lampsilis fallaciosa Smith. 



I have not seen the soft parts of this form, but I doubt very much 

 whether it is specifically distinct from L. anodontoides. Among my 

 specimens from Kansas River, there are some, to which this name might 

 be applied. Among other material likewise in the Carnegie Museum 

 1 1 annot sharply distinguish these two forms. 



Simpson (1900a, p. 75) says: "in L. fallaciosa there is a horny, 

 brown, raised streak on the inside of the mantle behind, that I do not 

 find in anodontoic This "streak," however, is also present in 



