THE NAUTILUS. - r )9 



and on the whorls three or four impressed spiral lines, which are 

 equally apparent on the ribs and intercostal spaces. 



This species occurs both recent and fossil in California. Recent 

 shells appear more slender with fewer ribs, 12-14. The type is a 

 fossil specimen from Dead Man's Id. off San Pedro, Gala., and has 

 8 whorls which measure : long 5.3 mm., diam. 2.2 mm. A recent 

 shell of 10 whorls measured 6.0 mm., diam. 2.1 mm. 



LIMNAEA AURICTJLARIA IN AMERICA. 



BY FRANK COLLINS BAKER. 



Some weeks ago Mr. Herbert E. Walter, instructor in Biology in 

 the North Division High School, brought me several specimens of a 

 Limnaea which was new to the fauna of the United States. Upon 

 inquiry, the locality was given as the propagating green-house of 

 Lincoln Park. A few years ago Miss Marie LaGrange, a pupil in 

 the North Division High School, found a number of the same species 

 in a lily pond in the park, the water of which was artificially heated 

 to give the necessary warmth for certain tropical plants, the tem- 

 perature being above 90 Fahr. 



Comparison with the shells in the Academy's collection showed 

 the species to be Limnaea auricularia, and an inquiry of the park 

 gardener brought to light the fact that certain plants had been 

 recently imported from Belgium. This information at once removed 

 the mystery surrounding the sudden appearance of this shell in the 

 park, and shows how easy it is at the present time to transport a 

 species from one continent to another, especially if it be a pulmonate. 

 The shells of L. auricularia are about an inch in length, of a deep 

 corneous color, and are rather thin. When alive, the mantle of the 

 animal is seen through the shell to be made up of dark and light 

 spots arranged irregularly. The animal appeared rather active, 



moving about the aquarium with a steady, gliding motion. The 



heart pulsations were 34 per minute. 



It may also be of interest to state that the following introduced 



species have been found in the greenhouse or in the lily ponds: 



Testacella haliotoidea, Limax maximus and L. flavus^ Vitrea drapar- 



naldi and Limnaea auricularia. 



