Quarterly Joiii'ual of Conchology. 215 



varieties of northern forms is yet an open question. Very few, if 

 any, of the Naiades have an equal distribution; and the same is 

 true of our Land Shells. In these facts are the data for much 

 profitable study, earnest field work and anatomical examination. 

 And when we find a stream, from whose pregnant waters one hun- 

 dred and eighty-two described species have been taken, and when 

 we reflect that two genera of these shells are confined to its limits, 

 the problem assumes proportions of interest not excelled by that 

 of any other stream in the world. Besides, its rocky banks^ of 

 Tertiary and Cretaceous sands and clays, crowded from base to 

 summit with remains of ancient life, render this region classic 

 .ground to the student of Palaeontology; and if the faces and sug- 

 gestions contained in this article, tend in any way co the fuller 

 understanding- of the anomalous fauna of this region, the object of 

 the writer will have been fully attained. 



Zonites glaber, (Studer), near Leeds. — V/hile collecting 

 shells on the 24th of Sfptember, 1S76, in company with my friend 

 Nelson, at the village of Shadwell, I took a specimen of this species, 

 this brings its occurrence nearer Leeds than hitherto recorded. — 

 H. Growth ER. 



Ancylus fluviatilis var. gibbosa, (Bourguignat). — I have 

 to record two new Yorkshire localities for this variety, one is a 

 small stream that runs into Lake Semmerwater in Raydale; the 

 other a small mountain stream near Gunnerside, in Swaledale. 

 In both the above places, I. took it about two years ago. — " 

 H. Growth ER. 



