MUSSELS OF CUMBERLAND EIVEE AND TRIBUTARIES. 49 



glochidia faaten readily to our common spiny-rayed fishes. Some gravid examples 

 of this form were collected by Mr. Boepple in the autumn of 1910 from the upper 

 Cmnberland and sent to the biological station at Fairport, and though the mussels 

 were dead the glochidia were still alive and attached themselves readily to fishes. 



This is the most desirable form with which to stock the river and extensive plant- 

 ings from the falls to the mouth would greatly increase its value as a muSsel stream. 



13. Lampsilis orbiculata (Hildreth), 



Fairly common in the middle portion of the river, usually from 1 to 3 examples 

 being found on each bed. 



We were struck with the remarkable similarity between this species and the south- 

 em mucket, Lampsilis ligamentina gibba. About the only way to distinguish between 

 them was by the bright orange shade of the epidermis, and usually orange tint of 

 the nacre of orbiculata, and it is easy to imderstand Call's « remark that Dr. Hil- 

 dreth and the earlier naturalists seem to have considered this shell as a variety of 

 Unio crassus Say (= Unio ligamentinus Lamarck, short and thick variety found in the 

 Ohio), but Call adds: "It certainly would seem to be a good species." Our own 

 studies and comparisons showed them more distinct than appeared at first o-lance. 

 The difference is most plainly seen in the female shells, which differ considerably 

 from the males, being truncate posteriorly and short and well swollen postbasally. 

 They are well represented by Say's b figure of Unio abruptus, and look somewhat 

 like a compromise between the southern mucket and L. ventricosa. Ortmann^ 

 says that this species "is not at all related to L. ligamentina as Simpson thinks; but 

 it belongs to the ventricosa group of Lampsilis, for it has a well-developed flap on 

 the mantle edge." 



L. orbiculata also very closely resembles L. higginsH which is more generally north- 

 em in its distribution, but the males of higginsii are shorter, more closely approach- 

 ing Obovaria ellipsis. Orbiculata and higginsii are probably closely related. 



This is a very good button species, but so uncommon that it is not much of an item 

 in the trade. 



14. Lampsilis txniata (Conrad). 



Rare; none at all were found in the Cumberland or in any of the tributaries except 

 Stones River. It appears to be a species of small clear streams, and was found in 

 the fine gravel at the edge of the water among the water-willows. 



15. Lampsilis picta (Lea). Painted mussel. 



Rather rare, and not taken by us in the main river. We found three in the Rock 

 Castle River a few miles back from the Cumberland. Mr. Boepple, in the autumn 

 of 1910, obtained it in the Big South Fork at Sloans Shoals, near Bumside. It ia 

 too small and thin to have any commercial value. Our largest example measures 

 61 mm. long, 33 mm. high, and 17.5 mm. in diameter. 



16. Lampsilis punctata (Lea). Spotted mussel. 



It is very like L. picta in color and outline, but differs in being more inflated and 

 in carrying its thickness to the edge, so that its ventral margin is rather rounded and 

 blunt, while that of picta is sharp. Both species are new to our collection. Mr 

 Bryant Walker, who identified them for us, called attention to the differences. The 

 shell is thick anteriorly, but thins out rapidly behind the center. It has no commer- 

 cial value on account of its small size, and most of our specimens are also badly eroded. 



17. Lampsilis perdix (Lea). 



Abundant in the Cumberland just below the falls. Mr. Boepple in 1910 found it 

 as far down as Rowena and in the Obey River at Celina. It is common in Rock 

 Castle and frequent in the Big South Fork. 



a MoUusca of Indiana, Indiana Geological Report, p. 493. 

 f> American Concliology, pi. 17. 

 c Nautilus, vol. xxin, no. 9, p. 119. 



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