crawling over the grass and even at the very edge of the water. The 

 animal seemed much too large for the shell; in fact, Professor Parker 

 told us that during the summer months the animal is not able to with- 

 draw completely into the shell, but that on the approach of winter it 

 becomes smaller, and is finally able to retract a considerable distance 

 within the aperture. The head 

 and neck of the animal were made 

 especially notable by the presence 

 of seven black lines. The eye 

 peduncles were short and blunt, 



and the foot was half as wide as (M^nS.) ValiS CmWling n 

 it was long. 



Professor Parker said that the species of this genus (Succinea) inhabit 

 moist localities, generally in the vicinity of water, and may be found 

 crawling about on the vegetation along the margin. They are some- 

 times found on tree trunks at a considerable height from the ground. 

 "Succinea retusa" continued the Professor, "is infested with a very 

 curious, sausage - shaped parasite called Leucochloridium americanum, 

 belonging to the fluke-worms, which modifies the tentacles to a large 

 extent. Some birds, the thrushes for example, eat the infected Succinea, 

 and the parasite develops in their intestines into the adult fluke-worm, 

 or Distoma. Some of the fresh -water Limnceas are infested with 

 a smaller worm, which changes into the fatal liver-fluke in sheep, 

 which love to feed upon Limnceas." 



In the moss which overhung a pool of clear water George found 

 a number of glossy, horn-colored, turreted shells, about a quarter of an 

 inch in length, which, we were told, bear the technical name Cochlicopa 

 lubrica. Not far from this spot Harry picked up a number of Succinea 

 shells from which the animals had been removed. They were of a beau- 

 tiful rich, transparent horn-color. Some smaller specimens of a different 

 species were of a rich rose color. 



Harry, who was the closest observer of the quar- 

 tette, discovered some minute shells about one-twelfth 

 of an inch long, which were white and pellucid, like 

 spermaceti. These, Professor Parker told us, were 

 members of the family Auriculidce, which includes 

 terrestrial shells that inhabit the vicinity of water. 

 Their shells were graceful, and when examined with a hand lens, were 

 very interesting. The other genera of this family inhabit salt marshes 

 in the vicinity of the sea: their shells are generally much larger, 

 and the apertures are filled with teeth. We spent the entire day in 



31 



Cochlicopa lubrica, 

 magnified. (Binney.) 



