THE MUSEUM. 



43 



Unio; in bars and shoals arc found im- 

 mense numbers of operculate univalve 

 mollusk?, and in the rapids, especially 

 in rocky portions of the principal riv- 

 ers, are found the beautiful and inter- 

 esting shells of species of lo, which 

 are the largest and most attractive 

 univalves of the family to which they 

 belong. The earliest account we have 

 of this group of shells may be found 

 in the /oiirital of t/w AiinLiiiv of Nn/- 

 ural SciciH-c^, November, 1S25, in 

 which Mr. Say described a species 

 found in the North Fork of the Hols- 

 ton River in \'irginia. calling it Fiisiis 

 flii: talis. From that time until quite 

 recently, additional species have from 

 time to time been published, all of 

 them being referred to the Holston 

 River or more vaguely to "Tennesee. " 

 Even so late as 1873, there was on- 

 ly a single record showing that lo had 

 been found in any stream other than 

 the Holston River. The record here 

 alluded to occurs in the American 

 Journal of Conchology. vi. 223, and 

 bears date October 24, 1870. If there 

 were any persons aware of the occur- 

 rence of lo in streams other than the 

 Holston River prior to that date, they 

 probably had reasons for not publish- 

 ing the fact. Since the date quoted, 

 however, it has been ascertained that 

 the distribution of lo extends to sev- 

 eral streams in East Tennesee, ren- 

 dering it quite probable that future ex- 

 ploration may lead to its detection in 

 the southern part of Eastern Ken- 

 tucky, and in the northern part of 

 Western North Carolina. At the 

 present time lo is known to occur in 

 the following streams: North Fork of 

 the Holston in Western \'irginia; in 

 the Holston River in East Tennesee; 

 in the Tennesee River as far south as 

 Bridgeport, Alabama; in the Nola- 

 chucky and French Broad Rivers in 

 Jefferson County, Tenn. ; in the Clinch 

 River at Black's Ford, Anderson Co., 

 Tenn. ; and at \\'illiam'sFord in Roane 

 County, Tenn. ; and in Powell's River 

 at Kreasborn's Ferry, near the State 

 of Kentucky. 



Observers who have made any re- 

 cords of the habits of lo agree in stat- 

 ing that the shells are found only in 

 swift water, tin '-^h there appear to be 

 discrepancies a.s 10 the abundance of 

 specimens which may indicate that 

 some localities are more favorable for 

 them than others. It must be inferr- 

 ed that lo, living in streams the cur- 

 rents of which are very rapid, is spec- 

 ially organized and adapted to the sit- 

 uations in which it is found. Such, 

 indeed, seems really to be the case; 

 for a lady who collected specimens in 

 some of the rivers of Tennesee wrote 

 of them as follows: "The muscular 

 power of lo is astonishing. I fre- 

 quently find one adhering to a rock 

 half as large as my head, and when I 

 take up the shell it brings the rock 

 with it, and requires much force to 

 separate it." 



It is somewhat strange that shells of 

 so much beauty as some of the species 

 of lo display are scarcely known to 

 the inhabitants dwelling in the neigh- 

 borhood of the streams in which they 

 occur; yet it seems, from records made 

 of the contents of ancient burial plac- 

 es, that they were known to the peo- 

 ple who inhabited the country prior to 

 the advent of European races. Mr. 

 Lea, writing upon this subject, makes 

 the following suggestive remark, which 

 conveys a good deal in a few words: 

 "Professor Troost informs me they 

 [los] are rare in the river [Holston]; 

 that they had been observed in the 

 graves of the aborigines; and as it was 

 generally believed that these were 

 'conch shells,' consequently coming 

 from the sea, it was urged that the in- 

 habitants who possessed them must 

 come over the sea. It does not ap- 

 pear that they [los] had been observ- 

 ed in their native element, though liv- 

 ing at the very doors of the persons 

 who had remarked them in the tumu- 

 li." The impression that lo is a "sea- 

 shell" is one that strikes most ordinary 

 observers at first sight, as every col- 

 lector who has them can testify. 



Quite a considerable number of spe- 



