14 THE NAUTILUS. 



In the Cheat River at present. Also in the Monongahela at 

 Charleroi, Washington County, and in the Ohio and Allegheny 

 Rivers from Beaver to Armstrong Counties. A species of the 

 larger rivers. 



We see, that of these thirteen forms one ( Truncilla perplexa cin- 

 chinatiensis) is not present any moi*e in western Pennsylvania, and 

 five {Truncilla perplexa rangiana, Lampsllis ventricosa ovata, Obo- 

 varia circulus, Cyprogenia irrorata, Unio erassidens) are not found 

 any more in the vicinity of Point Marion (in Cheat River or Dunkard 

 Creek). Of the latter, Lampsilis ventricosa ovata, Cyprogenia ir- 

 rorata, and Unio erassidens, are typical inhabitants of the large 

 rivers, and, near Point Marion, possibly once existed only in the 

 Monongahela River, the fauna of which is now destroyed. Truncilla 

 perplexa and Obovaria circulus may yet turn up in the Cheat River, 

 but, if present at all, must be very i-are at the present time. This is 

 the more remarkable, since the two forms of Truncilla perplexa were 

 represented, in the garbage heap, by a comj-aratively great number 

 of individuals. 



The small size of all specimens shows that the Indians selected 

 for food only such small specimens, rejecting the big ones. 



The chief interest of this little collection lies in the fact that it 

 gives us an idea of what damage has been done to our Unionida- 

 fauna in recent times. For comparison, I submit here the lists of 

 the species collected by myself in Cheat River and Dunkard Creek. 



Cheat River (collections made on Sept. 6, 1904, Sept. 16, 1907, 

 July 10, 1908). 



1. Lampsilis ventricosa (Bar.). 8. Symphynota eostata {'RsS.'). 



2. Lampsilis multiradiata (Lea). 9. Alasmidonta marginata {Say). 



3. Lampsilis ligamentina (hum.). 10. Unio gibbosus (Hnrn.). 



4. Lampsilis recta (Lam.). 11. Pleurobenia clava (Lam.). 



5. Lampsilis iris (Lea). 12. Quadrula undulata (Barn.). 



6. Ptychobranchus ph as eolus 13. Quadrula pustulosa (Lea). 

 (Hildr. ). 14. Quadrula subrotunda (Lea). 



7. Strophitus undulatus (Say). 15. Quadrula tuherculata (Raf.). 

 The leading species is Unio gibbosus (30 per cent.); then follow : 



Lampsilis recta (20 per cent.) and Ptychobranchus phaseolus (20 {)er 

 cent.). The rest (12 species) makes up the remaining 30 per cent. 

 The scarcity of Lampsilis ligamentina is remarkable, since this species 

 usually is the leading species in our rivers. Probably, this locality 



