THE NAUTILUS. 69 



whorl free from the body, as in Lyegyrus, a somewhat common 

 pathologic condition in species of this and allied genera; but in the 

 other and evidently normal specimen the peristome is quite free from 

 the adjacent body-whorl, not appressed thereto. Neither example 

 retains the operculum or dried soft parts, and therefore the generic 

 reference cannot be verified by examination of the dentition, but the 

 figure of the shell is that of a Bythinella rather than of an Amnicola. 

 It is a stumpier species than 1>. binneyi Tryon, and has far less 

 inflated whorls than B. brevlmma Pils., but these two species are 

 conchologically its nearest allies among United States species. Of 

 the short-spired Mexican forms, Amnicola orizabensis C. & F. is totally 

 diverse, although the figures in Crosse & Fischer's work (pi. 50, 

 fig. 4, a, 6) look somewhat like this species. A. guatemalensis C. 

 & F. is larger, with relatively smaller aperture. 



ISAAC LEA DEPARTMENT 



[Couducted in the interest of the Isaac Lea Conchological Chapter of the Agassiz 

 Association by its General Secretary, Mrs. M. Burton Williamson.] 



Every week the General Secretary receives letters from the mem- 

 bers of the Chapter telling of the benefits of Chapter membership. 



A good rule to follow in exchanging specimens is this : " Give a 

 little more than you receive." The one who exchanges merely to 

 add to the number of shells in his own cabinet, loses one nf the 

 great pleasures in life the blessedness of giving pleasure to others. 



NOTES ON SHELLS. 



[Report of Mrs. E. C. Soper. From the Transactions of the Isaac Lea < '<m ln'lM L ;i>al Chap- 

 ter of the Agassiz Association for 1894.) 



My enjoyment in studying shells is greatly lessened by the fact 

 that to obtain good specimens I must collect those that are 

 "alive," and then go through the intensely disagreeable operation 

 of killing the helpless animals. Though, as we are told, they are 

 not so sensitive to pain as the higher organisms, yet the poor, writh- 

 ing, quivering creatures appeal to my pity in a very great degree. 



However, men's cruelty, perhaps, does not surpass or equal that of 

 the winds and the waves, and of the stronger animals that prey upon 



