FRESH-WATER MUSSELS. 



165 



until the end of the season when the pond is drawn. The Lake Pepin mucket in con- 

 siderable numbers have been reared in earth ponds. A few pocketbook mussels, L. 

 ventricosa, were obtained after a recorded plant in a pond of modified type, having earth 

 bottom but wooden sides. Mussels of several other species have been found in ponds 

 from accidental plantings. The sporadic occurrences of young mussels in the first ponds 

 and in the reservoir constructed at the Biological Station at Fairport, Iowa, are of 

 interest as showing how, through parasitism upon fish, many species of mussel will 

 quickly invade new waters. It is significant that none of the species which have intro- 

 duced themselves abundantly into these ponds are commercially valuable. Apparently 

 the commercially useless mussels are more easily and abundantly distributed by natural 

 means than the useful ones. A list of the species noted, with additional data, is com- 

 prised in the followng table (cf. PI. XX) : 



Table 24. — Mussels Recorded from Ponds ax the Fairport Station. 



Scientific name. 



Common name. 



Number or frequency. 



Length in 

 millimeters. 



Anodonta corpulenta Cooper 



Anodonta suborbiciilata Say ° 



Anodonta imbeciUis Say 



Arcidens CDniragosus Say a 



Lampsilis ligamentina Lam 



Lampsilis (Proptera) alata Say 



Lampsilis (Proptera) capax Green. . . 

 Lampsilis (Proptera) Ixvissima Lea. 



Lampsilis subrostrata Say a 



Lampsilis gracilis Barnes 



Lampsilis parva Barnes « 



Obliquaha reiiexa Rafinesque 



Plagiola donacifonnis Lea 



Quadnila plicata Say 



Quadrula undata Barnes 



Strophitus edentulus Say a 



SyTDphynota compianata Barnes 



Obovaria ellipsis Lea 



Floater 



Paper-shell 



do 



Rock pocketbook. 



Mucket 



Pink heel-splitter. 



Pocketbook 



Paper-shell 



Abundant . 

 7 



7 



Paper-shell. , 



Three-homed warty-back. 



Deer-toe 



Blue-point 



Pig-toe 



Squaw-foot 



White heel-splitter 



Hickory -nut 



Abtmdant. 



....do 



....do 



....do 



Abundant . 



60-90 



67.4 



a-48 



39-49 



6-ao 



69.S 



49- S 



27-90 



8.48 



9. 1-7 I 



5-7-27 



16 



2.6-20 



13- S 



IS- 8 



62.1 



64-91 



II. 4 



a Uncommon in the river. 



(7) Experiments have also been made with various containers of small dimensions 

 which are usually supplied with running water. Such are the glass aquarium and the 

 tank or trough which may be made of wood, concrete, or sheet metal. Of these the one 

 most used for experimental rearing of mussels at Fairport, Iowa, has been the trough of 

 sheet metal painted with asphaltum. A special arrangement for water supply is em- 

 ployed. The water is not taken directly from the main reservoir, but is drawn from the 

 surface of a pond containing vegetation ; in some cases it is also strained through cloth. 

 In this way water is obtained that is very clear and probably free to a large extent from 

 such small animals of the bottom as would pre}' upon the young mussels. The Lake 

 Pepin mucket, the river mucket, and the yellow sand-shell have been reared through the 

 first year in such troughs. The experiments are of such importance as to merit detailed 

 description. The following account is based upon a report of F. H. Reuling, who first 

 assisted in the experiments and later was charged \\-ith their conduct. (See also Reuling, 

 1919.) 



The experiments were conducted in a series of eight galvanized iron troughs, placed 

 at a sufficiently low level to receive a gravity supply of water from pond i D. This pond 

 was supplied by gravity from the reservoir which received its supply direct from the 

 Mississippi River through the pumping plant. The water in pond iD remained com- 

 paratively clear throughout the season, and this was one of the primary considerations 



