JOURNAL OF CONCHOLOGY. II5 



claims to have correctly identified for the first time since it was 

 originally described, Say's P. glabratics. 



Mr. Gray in Science News records the diffusion in America 

 of Litorina litorea. Other papers by Dr. Cooper, Mr. Stearns, 

 Mr. Calkins, Prof. Packard, are also enumerated by Mr. Dall in 

 this article. 



ON THE ASSOCIATION OF LIMN.^A GLABRA, 

 PHYSA HYPNORUM h^V) PLANORBIS SPIRORBIS. 



By W. nelson. 



I should wish to call the attention of our members to 

 recording the instances of the occurrence of different species 

 found in company. Being most interested in water species, my 

 attention has been more particularly given to them. Taking no 

 note of such widely spread and common species as Z. peregra 

 and L. truficatitla which may be said to occur everywhere, 

 I have myself generally found L. glabra associated with Planorbis 

 spirorbis and Physa hypnoriwi. At Spark Hill, Birmingham, Z. 

 glabra was the most abundant species in the ditch, Planorbis 

 spirorbis the most scarce. At Acock's Green near Birmingham 

 the three species are equally common. At Stanley near Wake- 

 field the Z. glabra is very rare, and at Castleford it is the most 

 common of the three. Excluding the Z. glab7-a which is the most 

 local of our common Limnceidce, I find Planorbis spirorbis and 

 Physa hypnorum are often associated together. The only place 

 where I have found Physa hypnorum and not yet detected 

 Planorbis spirorbis is in a grassy ditch at Leventhorpe pastures 

 near Leeds. 



At the undermentioned places I have found the following 

 species together: — 



