Bii.i,. I'. S. ]'.. I-"., 1919-20. 



Plate XI \ 



[Figures from Lek-vrc iiiid Curtis. 1912.] 



Figs. 1 and 2. — Hooked glochidium of ^ymphynota coslata. 



Figs. 5. 4, and 5. — Hooklcss ;:lochidiuiii of LampsHis subro- 

 strata. 



Figs. 6 and 7.— Ax-licad clocliiditun of Lampsilis (Prop- 

 Icra) alata. 



Fig. S. — Con^lutinates (masses of glochidia) from the thrcc- 

 horncd warty-back. Ohliqiuiria rcficxa. 



Fig. <>.— i'urtion of con^Iutinate of Obliqitaria rcflexa, 

 nngiiificd. Glochidia still within cuk membranes wliicli 

 are closely pressed and adherin^j together. 



Fig. 10. — Conglutinatcs (masses of glochidia) from the 

 mucket. Lainpsiiis Iwamcntina. 



Fig. II. — ^ Portion of conglutinate of LampsHis lioawcntma 

 magnified. Glochidia inclosed in membranes are embedded 

 in a mucilaginous matrix. 



