THE NAUTILUS. 101 



Shuttleworth (1. c. p. 98). But it is very improbable that it 

 is really Haldeman's specie?. 



All this leads to the very definite conclusion that A. obscurna 

 Hald. is restricted to the head-waters of the Tennessee system 

 in Virginia and Tennessee and does not occur in Florida or the 

 West Indies. 



Clessin (Con. Cab., Ancylus, p. 14) designated A. obscurus as 

 the type of his group, Haldemania. As both ihe genuine ob- 

 scurus and the species that he took for it are Lsevapices it is 

 immaterial which should be considered to be his type. Halde- 

 mania having been preoccupied by Tryon (1862), Clessin' s 

 name can not be used and must fall into the synonymy of 

 Lsevapcx. 



II. 



FERRISSIA (L/TCVAPEX) OBSCURA (Hald.).* 



Ancylus obscurus Haldeman, Mon., 1844, p. 9, pi. I, fig. 5; 

 W. G. Binney, L. and F.-W. Shells, Pt. II, 1865, p. 139, fig. 

 232. 



Haldeman's unique type came from the Nolachucky River, 

 below Greeneville, Tenn. It measured: Length 5, width 3.5, 

 alt. 1.5 mm. I have before me three specimens (Coll. Walker, 

 No. 36292) collected by Goodrich in the South Fork of the 

 Powell River at Big Stone Gap, Wise Co., Va. They measure 

 respectively: Length 6.5, width 5, alt. 2.5 mm.; length 6.3, 

 width 4.5, alt. 2 mm.; length 5.3, width 4, alt. 1.5 mm. 



It will be noticed that the dimensions of the smallest speci- 

 men agree quite exactly with those of Haldeman's type. It 

 also agrees in other particulars with his description and I have 

 no doubt but that it is the same species. If so, the type was 

 not fully matured and the largest specimen given above and to 

 be figured hereafter represents the fully matured form. As 

 shown by the figures it is an obovate shell, broadly rounded 

 anteriorly and regularly, though more narrowly, rounded pos- 

 teriorly, the lateral margins being about equally curved; the 



*The species will be figured in connection with the concluding part of this 

 paper. 



