16 THE NAUTILUS. 



and at the same time looking for pearls. They have some common 

 names for certain kinds of mussels; and an oflScial of button fac- 

 tories I met at Marietta, was kind enough to verify the names and 

 to give some additional information. 



"Mucket." Lampsilis ligamentina, also orbiculata. 



" Pig-toe." Quadrula obliqua, and the whole group of approxi- 

 mately the same shape, also suhrotunda, xsopus, etc. 



'' Warty pig-toe." Q. cooperiana, pustulosa, etc. 



"Nigger-head." Q.ebena; someiixaes ?^\so Obovaria retusa. 



" Monkey face." Q. metanevra. 



" Butterfly." Plagiola securis. 



" Pocketbook." L. venti-icosa, also capax. 



" Sand clam," or '< Black sand clam." L. recta, occasionally also 

 Unio gibbosus. 



" Lady's finger." L. anodontoides. no doubt also fallaciosa. 



" Three-ridge washboard," or " Three-ridge," or " "Washboard," 

 Q. undulata, also plicata, and multiplieaia. 



" Razor-back," " Rudder-back," '< Hatchet-back." Proptera 

 alata (and, no doubt, Symphyn. complanatd). 



Some other large and common mussels may have common names, 

 but I failed to find them out, e. g. U. crassidens, Tritogonia, Q. 

 lachrymosa. 



ON THE VALIDITY OF UNIO UNDATUS BAENES. 



BY BRYANT WALKER. 



(^Concluded from p. 10. ') 



III. 



Is U. undatus Bar. = U. trig onus Lea. 



Lea's description of his trigonus is as follows : 



" Shell subtriangular, inflated, nearly equilateral, depressed before 

 the umbonial slope, angular behind ; umbonial slope carinate ; basal 

 margin emarginate ; substance of the shell thick, beaks prominent, 



