MUSSELS OF CUMBEKLAND EIVER AND TRIBUTARIES. 41 



Another buyer reported 500 tons obtained from the same region 

 of the Cumberland by his company during each of the years 1907, 

 1908, and 1909, but only 100 tons in 1910. 



In addition to these companies there were Ohio River parties and 

 private fishermen operating in the river, which must have increased 

 the annual output to considerably over 2,000 tons per year. 



Because of the drop in prices mentioned above, none of the Lirger 

 companies were operating the river during 1911 with the exception 

 of ]\Ir. Walter, at Dover, Tenn., and the blank factory at Clarksville, 

 Tenn. 



BREEDING SEASON OF THE CUMBERLAND MUSSELS. 



Throughout the progress of the survey the various species of mussels 

 were examined as to breeding condition and the date at which the 

 various species were found gravid is shown in the table following. 

 In addition to the table, which gives only the bare facts, the follow- 

 ing additional notes will prove of interest and value. 



The only Lampsilis ovata found gravid was on May 13. ^Ir. Boep- 

 ple sent in some gravid examples during the late autumn of 1910. 

 Without doubt this species is usually gravid from autumn until the 

 next spring. L. multiradiata was found becoming gravid July 28. 

 In other streams we have found it fully gravid in September and 

 October. Lampsilis anodontoides was found fuUy ripe in abundance 

 from June 10 to 21. The breeding season of this species is well 

 known; it usually becomes gravid in autumn and remains so during 

 the winter. Quadrula perplicata was noticed becoming gravid May 

 24, and gravid samples were still found July 27. Although Quad- 

 rula cooperiana remained gravid for a considerable length of time, 

 we saw only a few samples; the citations refer to single individuals, 

 so that, while we have it recorded from June 3 to August 11, 

 only 11 gravid examples altogether were seen. The characteristics 

 of the gravid mussel are described under the discussion of the species. 

 It is a desirable species to propagate. Quadrula obliqua is the most 

 proUfic mussel in the river, and we saw many more gravid examples 

 of this than of any other species. From June 3 to 10 is the height of 

 its breeding season, and at that time about haK the catch obtained 

 would be gravid. When the hfe history of the species is laiown and 

 the fish which serves as host, it will be easy to procure material for 

 propagation during a considerable part of the summer. 



Quadrula ehena was observed in early stages of gravidity about the 

 beginnmg of the work, and gravid examples were obtained as late as 

 July 16. The other species noted are not of special economic impor- 

 tance and gravid examples were found only in small numbers. Suffi- 

 cient information about them can be obtained by a glance at the 

 table. 



