•_'44 Annals of mr Carnegie Museum. 



Fusconaja lananensis (Frierson). 



Fricrson (1901, p. 76) describes the sofl parts as; "salmon-colored, 



scarlet when cut" (probably sexual glands). "Eggs carried in all 



four gills, very red." This, together with the general shape of the 



shell, renders it almost certain thai this species should be placed here. 



Fusconaja subrotunda (Lea). 

 1 have investigated numerous individuals in all conditions collected 

 by myself in the Ohio and Allegheny Rivers in western Pennsylvania, 



and some additional ones from the Ohio between Pittsburgh and 

 Cincinnati. 



The breeding season falls in June and July. 



The soft parts have been described b\ l.ea (Obs., X. 1863, p. 427). 



This species agrees well with F. rubiginosa, but special mention 

 should be made of the anal opening, which has line crenulations, and 

 -hows the same variability as regards the short mantle-connection 

 separating it from the supra-anal. The structure of the gills (see 

 Ortmann, 1911&, pi. 86, tigs. 1-3) is essentially the same as in F. 

 rubiginosa. 



The ova are generally red, but in rare instances they are pale pink 

 or white. The placenta' are also subcylindrical. and are discharged 

 whole. The glochidia are similar to those of F. rubiginosa. but slightly 

 higher than long.* Length 0.13 mm.; height 0.15 mm. 



In the color of the soft parts, two types may be distinguished. 

 Normally there is much orange color present, which is most intense 

 (deep orange-red) on the foot, the mantle margins, and the adductors, 

 while the rest, chiefly the gills, are more brownish. When charged 

 the gills are red. In the other type o\ color all parts are whitish or 

 yellowish, or brownish-white, the latter color chiefly on those parts. 

 which are orange in the other type. Yet there are intergrades between 

 these two types, the orange color gradually passing into the brown. 

 In western Pennsylvania, the orange type prevails. There is no re- 

 lation of these colors to sex. 



The color oi the gonads deserves special mention in this species for 

 comparison with the next. In all specimens examined it is either whitish 

 or paler or deeper red. the latter of a distinct crimson hue. identical 

 with the color of the eggs, but generally more intense. This crimson 

 i> found both in the male and in the female, so that it seems that also 

 the sperm is thus colored. 



