2 l6 



NOTES on MOLLUSCA. 



Unusually fine Planorbis nautileus at Colton, near Leeds.— In 



the early part of April I was taken by my neighbour, Mr. Smith, to a pond 

 in School Lane, Colton, near Whitkirk. At one end of the pond Callitriche 

 grew most luxuriantly, and searching- amongst it I found Planorbis nautileus 

 very plentiful and more finely grown than I have met with it before, some of 

 them measuring nearly 4 mm. in diameter. Amongst the grass growing 

 round the margin of the pond a few small Limncea truncatula occurred, but, 

 strange to say, there was no trace of Limncea peregra. — Wm. Nelson, 

 Crossgates, Leeds, 18th May 190 1. 



Molluscan Gatherings near Brigg, Line. N. — Our vicar, the Rev. 

 E. Adrian Woodruffe-Peacock, M. C.S., offered the school children a number 

 of little prizes for the best gatherings of our local species of snails. The 

 result was not satisfactory from the collector's point of view. Hundreds of 

 specimens were g'athered, but the species were limited ; only a very few 

 being interesting. Helix aspersa, H. nemoralis , with a beautiful compressa 

 variety and two fair conica. H. arbustomm is plentiful here, and the 

 varieties fnscesce?is , cincta, flavescens, and albina were taken. H. cantiatia 

 had also been taken. There was one H. caperata, and it was the variety 

 ornata, never taken alive in the parish before. There was one H. rufescens , 

 and it was the variety alba, which was also new. This was strange, as the 

 type and albo-cincta are common enough, even in the school garden. The 

 Ancholme river, which was partly run off, supplied Dreissensia polymorpha 

 only. Our next gathering will be later in the summer, and it is to be hoped 

 will be more productive. — Wm. Booth, Howsham School, Lincoln, 13th 

 June 1901. 



Reversed Limnaea peregra in Leeds. — There is a saying that 'All 

 things come to the man who waits,' and surely there must be some truth in 

 the axiom, for after collecting the Limnasidag continuously for quite forty 

 years, during which time I must have walked many hundreds of miles, 

 searching the ditches and ponds of our county, and must have passed many 

 thousands of specimens of" Limncea peregra through my hands, it was not 

 until the beginning' of the present month that I succeeded in finding the 

 reversed form of this species. 



During the first week in May I searched a pond situated in North Leeds 

 which I had hitherto altogether overlooked. After searching some time 

 I obtained specimens of the following Limnaeidae : — Planorbis albus, mode- 

 rately fine and common ; Planorbis carinatus, very fine and common ; 

 Planorbis corneus, rather fine but very scarce ; and Limncea stagnalis var. 

 fragilis, very common and appearing to be enjoying itself floating foot 

 upwards on the surface of the water. Limncea peregra, on the other hand, 

 was crawling on the muddy bottom of the shallow side of the pond ; they 

 were very fine grown shells of the ovata form, and after scooping a sufficient 

 supply out with my net I was just for starting home when, having made 

 what I thought was my last dip, I was at once struck by the singular 

 appearance of one of the specimens, and could scarcely believe my eyes. 

 It was, however, undoubtedly a specimen of monst. si?iistrorsum. I will 

 not attempt to describe my feelings, which can be readily imagined by any 

 field naturalist who has suddenly found a long-sought-for rarity. After 

 safely boxing my prize, I need scarcely say that I restarted searching with 

 renewed vigour and care, peering into the shallow parts of the pond which 

 the Limncea peregra frequented, and putting every specimen that came 

 within my vision through a critical examination. After a couple of hours' 

 searching I found a few more beauties of the reversed variety. 



The only vegetation I noticed in the pond was a grass which grows 

 a considerable length, half of which lies on the water, and one of the water 

 starworts {Callitriche). — Wm. Nelson, Crossgates, near Leeds, 18th May 

 1 901. 



Naturalist, 



