Fragments of Natural History. 



167 



In company with my friend J. G. Anthony, of Cincinnati, we 

 found great numbers of young Uniones on a sand-bar in the Ohio 

 river, near that city. The water was clear, rapid, and about 

 eighteen inches deep, offering the most favorable circumstances 

 for the accomplishment of our purpose. The young were gene- 

 rally imbedded in sand and pebbles to the depth of three or four 

 inches, and when carefully raised from their retreats were always 

 found to be furnished with the filament above described. Oa 

 tracing out the extremity, remote from the body, we discovered 

 it to be attached indiscriminately to pebbles, stones, the shells of 

 older specimens, or other fixtures. The purpose it is destined to 

 accomplish, instead of being an umbilical connection with the 

 mother, as I formerly supposed, is evidently that of a cable, to 

 anchor the young in safety in a favorable locality, at an age when 

 they are unable to do it by other means. It is in fact a byssus, 

 similar in many respects to that with which the Chama and cer- 

 tain other bivalves are furnished, and by means of which they 

 adhere to other bodies, 



Fis. a. 



Fig. I. 



Fig. a represents a vertical section of the river, exhibiting a 

 young U. zigzag raised out of its bed, but still attached to a stone. 



Fig. 6, the origin of the byssus at the base of the foot of the 

 animal. 



