THE NAUTILUS. 41 



In conclusion, I Avould like to say a few words about collecting 

 these puzzling shells. In common with others of the family, they 

 arrive at maturity in the spring, and the adults are generally dead 

 by midsummer. Those taken later in the season will be young and 

 immature. It is more difficult to collect in the spring, when the 

 water-courses are full to overflowing, but I have had little trouble since 

 adopting a simple suggestion from my friend, George J. Streator, of 

 Garrettsville, O. An ordinary wire dish-cover tied to a long pole is 

 an effective scoop, and the meshes are fine enough to prevent the 

 escape of small shells, while yet the mud can be washed out. Young 

 shells wall often be found within the adults, and should be saved, 

 because in making exchanges, a set showing various stages of growth 

 is the most useful for study and comparison. 



NEW VARIETIES OF WESTERN LAND SHELLS. 



BY HENRY HEMPHILL, SAN DIEGO, CAL. 



Helix ptychophorus var. castaneus Ilemiihill. 



Shell umbilicated, globosely depressed, of a dark chestnut color; 

 surface covered with coarse, irregular, wddely separated lines of 

 growth, and crowded, microscopical revolving lines ; whorls oh, 

 convex, the last slightly descending in front, spire elevated ; suture 

 well impressed, aperture subcircular ; lip white, reflected and 

 partially covering the umbilicus, its terminations ajiproaching ; um- 

 bilicus small and deep. 



Height 8 inch, diameter 1 inch. 



Habitat, Old Mission and Rathdrum, Idaho. 



I regard H. ptychophorus as the progenitor of what I call the 

 Towsendiana group of west coast land shells, and this colored vari- 

 ety seems to still further indicate its relationship to Toivnsendiana, 

 for the spire whorls of nearly all the specimens of Townsendiana 

 that I have collected are chestnut colored. Townsendiana does not 

 begin to put on its wrinkles until it has made about four revolutions 

 of the shell. The wrinkles are probably due to its environment. 

 Helix tudiculata var. subdolus, Ilemiihlll. 



Shell nari'owly umbilicated ; globosely dej^ressed, of a dark yellow- 

 ish color, surface somewhat shining, covered Avitli oblique strife, 



