Crowther : Whitby. 



83 



land and fresh-water shells. The beach and the base of the cliffs will 

 repay a careful search. At Hawsker, on our way to the bay, we took 

 in a large pond the var. omta of Z. peregra, apparently the sole occu- 

 pant, as not another mollusc could be found. 



On the way to Ruswarp, a pretty little village on the Esk, and 

 somewhere about one mile from Whitby, we took the following fresh 

 shells: — Pupa umbilicata plentifully, Succinea putris, Limncea truncatula, 

 and Clausilia rugosa rarely. The coleoptera were almost as elsewhere, 

 the additions being Aphodim rufipes, Bembidmm ceneum^ Notiopliihis 

 semipunctatus, and Agriotes sputator ; on our return. Helix liortensis. At 

 the locality where the latter was taken are found both H. nemoralis and 

 Tiyhrida the variety. The three taken in conjunction at once point to 

 the beautiful pink-lipped hybrid form being an offspring of the dark- 

 lipped nemoralis and the white-lipped liortemis. From other observations 

 made elsewhere this year on the same point, we are fully convinced that 

 these two are the progenitors of the aptly-named hybrida. Limax fiavus 

 is abundant at Bagdale, on the outskirts of Whitby. 



The river Esk (Celtic for water) yields TJnio margaritifer, the pearl- 

 bearing mussel, a specimen of which, particularly to the Yorkshire con- 

 chologist, is a desideratum. The gift of a specimen gave us the desire 

 to take it for ourselves. A return ticket was taken to Egton Bridge, 

 and we worked our way up Glaisdale towards Lealholm Bridge. A 

 careful search from point to point disclosed at last an indubious sign in 

 the form of a piece of the black epidermis appertaining to this species. 

 Here we began to work. A net is useless ; the best, in fact the only 

 way to be successful is to take off shoes and stockings, roll up the 

 trousers as far as possible — fastening them with straps is advantageous — 

 and go into the stream. A stout stick is necessary for support, as the 

 stones are rough, and a step at times making a difference of a few inches 

 or as many feet of water. At last one was found, and an hour's searching 

 brought several to light, and two hours more raised the total to over 

 twenty. We were not successful every time we essayed, but learned 

 that they abound mostly about two feet from the sides, under bushes, 

 and in shallow water. The whole of the specimens were embedded 

 three:quarters of their length in mud, sand, and gravel, a good pull 

 usually being required to extract them. Doubtless it is to this latter 

 fact that is due the decomposition which obtains on the umboes, as from 

 their oblique position having the anterior end buried, the ventral edge 

 uppermost, with a gape of about three-eighths of an inch displaying the 

 edges of the mantle, and the posterior end well pointed up stream, the 

 umbonal region when the shell recUnes thus, must rest in the deepest 



