72 



musseij fauna of maumee rivek. 



of marketable shells in the river are Larnpsilis ligamentinus, and the 

 most valuable native species is L. rectus. 



The species of mussels to be recommended for propagation natur- 

 ally varies with different rivers. In the Maumee, the species gener- 

 ally regarded as the best button shell, the niggerhead, Quadmla 

 ehena, could not be recommended as it is doubtful whether it would 

 thrive in the shallow water. On the other hand, the mucket, Lamp- 

 dlis Ugamentinais, in many waters a poor or indifferent shell, is here 

 remarkably large and thick, with nacre of an excellent luster, and is 

 the best button species found in the river. This should be planted 

 extensively as the main crop. Plagiola securis, the butterfly, would 

 probably thrive in the water below Defiance Dam, and Symphynota 

 costata would be well worth trying, especially in canals with black 

 muddy bottoms, as it would be nearly certain to attain to unusual size 

 and thickness there, and might rank as a good button shell. 



The status of Z. rectm is peculiar. In many streams and rivers this 

 species is valueless on account of small size or purple nacre or both ; 

 in the Maumee it has large size and white nacre and is the most 

 valuable species per pound native to the river. With enough button 

 shells in the river to bring this species to the market it would be de- 

 sirable to plant rather heavily of it. It would make a good export 

 shell and yield the clammer much more revenue for work done and 

 material handled than the button species. 



The most valuable of the fresh-water mussels, Lampsilis anodon- 

 toides^ would be well worth a trial. It is not native to the river, but 

 there is every reason to believe that, like its close relative L. rectus^ 

 it would grow and thrive considerably better even than in rivers 

 where it is native. Good shells of this species bring an unusually 

 high price on the market. 



As regards mussel parasites, the river appears to have about the 

 average number as compared with other streams examined. They 

 are usually most abundant in thin-shelled species in quiet waters. 

 As regards pearls and pearly growths, which are closely related to 

 parasites, these are few. The distomid of Kelly and dorsal baroques 

 are rare. Eound pearls, all very small, were occasionally found, 

 and all these appear to owe their origin to the marginal-cyst dis- 

 tomid, which is quite common.'^ 



" Since this was written, we have found several minute pearls which were formed about 

 eggs of Atax. 



O 



