128 THE N4UTILU8. 



curved, sigmoid ; epidermis strong, olive-brown with a few darker 

 concentric streaks ; concentrically striate, nearly smooth. The left 

 valve has a slight ridge extending from the beaks to the posterior 

 extremity. Cavity of the left valve very shallow, of the right valve 

 deeper ; nacre purplish Hesh-colored. The left valve has two widely 

 separated cardinal teeth, lateral teeth remote from cardinals, double ; 

 right valve with single cardinal and lateral teeth. Height 32, width 

 53 5, thickness 18 mill. 



The specimen is said to be from China. It is from the collection 

 of I'abbe Provancher, Cap Rouge, Quebec. 



The ends are not produced as in A. contorta Lea, nor is the shell 

 bow-shaped like that species. It can be compared with none other 

 know^n to me. 



[Contributed.] 

 AMERICAN ASSOCIATION OF CONCHOLOGISTS. 



FEBRUARY 23, 1891. 



Since our last announcement the following new members have 

 been enrolled : 



139. E. R. Mayo,' Boston, Mass. Massachusetts Mollusca. 



140. R. T. Shepherd, Piqua, Ohio. Unionidae. 



141. Elwood Pleas, Dunreith, Ind. Indiana Mollusca. 



142. Hale Montgomery, Clinton, jNIo. 



Nearly all of the North American Concbologists and many 

 Palaeontologists are now enrolled in the Association, the progress of 

 which has been very gratifying. The members are taking advan- 

 tage of their privileges to correspond with each other, and much 

 special study has been accomplished. Several of the members have 

 undertaken the preparation of lists of species, similar to the list of 

 Haliotidae recently published by the President. A list of the 

 American Cypraeidae (fossil and recent) is now ready, but for want 

 of room, will not appear until next number. Several other lists are 

 approaching completion and we trust that it will not be long before 

 we have complete lists of all North American mollusks. 



The United /States Collection. 



The collection of United States shells, now being formed by the 

 members is growing very rapidly. Many species have been added 



1 Deceased since his election. 



