10 THE NAUTILUS. 



dSprimee vers F autre extremite, hisiUonnee sur le cote anterteur. Long- 

 ueur apparente, 61 millimetres. " 



This description taken by itself is too imperfect to be recognizable. 

 Dr. Lea himself so declared in 1829 (Obs. 1 p. 36) and consequently 

 omitted it entirely from his Synopsis of that date. 



Prior to Dr. Lea's visit to Paris in 1832, owing to the indefinite 

 character of Lamarck's descriptions, there was great uncertainty and 

 considerable diversity of opinion among American conchologists in 

 regard to nearly all of his species. And it was no doubt owing to 

 that fact, that Barnes, in describing his undatus, intimated that it 

 might be the obliquus of Lamarck. Dr. Lea never figured or de- 

 scribed ohliquus. But there can be no doubt but that the well-known 

 species, which for the last fifty years at least has been called by that 

 name, was determined by him as being the Lamarckian species. 



But his decision did not meet with universal acceptance. 



Ferussac in 1837 {loc. cit.^, in whose possession were many of 

 Lamarck's types, and who no doubt had access to the type of o6- 

 liguus, which was then in the museum in the Garden of Plants at 

 Paris, and after Dr. Lea had spent eight mornings critically exam- 

 ining and identifying his collection of American Unionidse, believed 

 that Lamarck's ohliquus was the species described by Lea as ebenus. 



And Conrad in his " Synopsis " of 1853 held to the same opinion,' 

 remarking that " Lamarck's description is wholly inapplicable to 

 undatus, which is not oblique, and certainly not *^ ovate-rotwidate." 



"What Lamarck's obliquus really is, can probably be only deter- 

 mined by a critical re-examination of the original type, if it is still 

 in existence. 



But whatever it may be, it is certain that if the current accepta- 

 tion of obliquus is correct, then it is clear that Lea's reference of 

 undatus to it was erroneous. On the other hand, if Lee was right 

 in his determination, then it is equally certain that the species now 

 known as Quadrula obliqua cannot bear that name. 



What it should be called in that case is " another story " as Kip- 

 ling would say and may well be held in abeyance until we know what 

 Lamarck's obliquus really is. And until that is definitely determined, 

 it is, no doubt, the better part to consider the shell we call obliquus 

 to be Lamarck's species and for the time being to deal with Barnes's 

 species on that basis. 



(7b be continued.) 



