88 THE NAUTILUS. 



'14. Of three males and four gravid females, all with glochidia, 

 two of them discharging, the soft parts have been preserved. 

 The breeding season thus ends in May. 



The anatomy is the same as that of the genus Alasmidonta, 

 as described previously (Ann. Carn. Mus. 8, '12, p. 297), also 

 with regard to color (inclining to yellowish and orange tints). 

 It should be mentioned that the inner lamina of the inner gills 

 is, in two males and two females, entirely connected with the 

 abdominal sac (as is the case in A. inarginata) ; but in one male 

 and two females, it is free in the posterior half or one-third of 

 the abdominal sac. The specimens with the inner lamina 

 partly free are the smaller ones. 



Glochidia as usual, triangular, with hooks, about as high as 

 long, L. and H. from 0.29 to 0.32 mm. Thus they are smaller 

 than those of A. marginata, where the L. is 0.33, the H. 0.36 mm. 



PAGIAS FABULA (LEA). (Ortmann, 1. c., p. 562.) 



Anatomy described in NAUTIL. 28, '14, p. 65. Gravid females, 

 with glochidia, were at hand, collected on Sept. 17, '12. An 

 additional gravid female, with eggs, has been found on Sept. 7, 

 '13. This indicates the beginning of the breeding season in 

 September. 



PTYCHOBRANCHUS SUBTENTUM (SAY). (See: Ellipsaria subt., 

 Ortmann, 1. c., p. 564.) 



The soft parts have been described in Ann. Carn. Mus. 8, '12, 

 p. 308, fig. 5. Many specimens have been secured subsequently, 

 confirming this account. It should be added that large females 

 show that the folds of the mareupium are more numerous, and 

 occupy nearly the whole outer gill. 



Gravid females have been found frequently from Sept. 5 to 

 Sept. 21, but with eggs only, indicating the beginning of the 

 season; on May 20, '13, females discharging placentae with 

 glochidia have been observed, indicating the end of the season. 



DROMUS DROMAS (LEA), D. DROMAS CAPERATUS (LEA). (1. c. , 

 p. 566.) 



Anatomy: Ann. Carn. Mus. 8, '12, p. 315, figs. 18, 18a, 18b. 

 The soft parts of the var. caperatus are absolutely identical 



