OP CONCHOLOGY. 213 



cannot be the same, but Mr. Rowell's specimens from " Oregon " 

 agree very well with anachoreta^ and Dr. Newcomb's is either 

 an extreme variety or a new species, I cannot say which, having 

 none of either form to compare. 



^^11. jyedestris," Gould, 1846 (animal excl.), wrongly credited 

 to New South Wales, but in " Otia," p. 243, made a synonym 

 of Toivnsendiana, describes a small variety almost of the size 

 and proportions of anachoreta. It may do for the var. of the 

 former without wrinkles. 



APLODON, Eaf. 



In my " West Coast Helicoid Land Shells " I considered this 

 also a subgenus of Odotropis, as it was formed in the same year, 

 having supposed that the type A. nodosum was IT. ? monodon, 

 var, Leaii, which appears to answer the description of both genus 

 and species. The genus, "aperture rounded, columella with a 

 single tooth,' umbilicated," was thus contrasted with Stenotrema, 

 which had been just described, and of which the type S. convex- 

 um {=ir. stenotrema, ¥er., two years later) nearly resembles 

 monodon externally. A. nodosum has " 3 [upper] whorls em- 

 bossed, lightly wrinkled concentrically beneath," the " emboss- 

 ing " referring to the tubercles left by the bristles in worn spe- 

 cimens, and the " concentric " wrinkles probably meaning ra- 

 diating growth lines. 



IT. monodon has been until lately considered a close ally of 

 Columbiana, but the discovery of an internal "fulcrum" in 

 Stenotrema,* also found in monodon, has induced many to put it 

 in that genus in spite of its wider mouth. If this character is to 

 be the essential one of the genus (which is very improbable), 

 Columbiana cannot be congeneric Avith monodon, nor germana 

 either, according to Bland's testimony. The two forms so named 

 by me as inhabiting this State both seem to want the fulcrum, 

 but otherwise appear distinct, a few only being found intermedi- 

 ate as in other groups. 



If the name Aplodon is not wanted for the monodon group, it 

 may do for the bristly section of Odotropis to which Columbiana 

 seems to belong. 



A. Columbianus, Lea (Cp.) Many large typical specimens 

 brought from Sitka by Mr. Harford have the animal uniform 



* Eaf. altered this to Stenostoma in 1819 and 1831, having used the for- 

 mer name in 1815 differently. — Binney's Bibliography, ii, 283. 



