82 , Field Notes. 



from two ponds not far apart, both on Chalky -Boulder -Clay ; 

 wild ducks and water-hens visited 24th December, 1917. 

 All the three ponds referred to in summer have a fauna of 

 water-beetles. — T. W. Woodruffe-Peacock, Grayingham, 

 Kirton-in-Lindsey. 



Early Mollusca in Yorkshire and Lincolnshire. — The 



preceding records emphasize the indifference to cold of the 

 slugs generally, few or none of the species being close hiber- 

 nants, and contrast strikingly with the keen sensitiveness to 

 cold of the thick-shelled Helices as Helix aspersa, H . pomatia, 

 etc. The occurrence of the pale and reticulate forms of 

 Agriolimax agrestis may probably be ascribed .to the com- 

 paratively mild winter we have so far enjoyed, as according 

 to many keen observers A . agrestis tends to darken at the fall 

 of the year, a circumstance ascribed to the usually moister 

 conditions and lower temperature. Mr. Peacock's notes on 

 the occurrence of Pisidiitm casertanuni and P. personatnm are 

 welcome, but it is a matter for regret that the name casertanuni 

 continues to be employed, for not only is there no certainty 

 that the identification with Poll's species is correct, but the 

 description given by Poll is very vague and unsatisfactory, 

 and the name being polynomial is inadmissible. The finding 

 of P. casertanuni and P. personatnm in the same restricted 

 habitation is also interesting, in view of the possibility of 

 their being only the forms of a single species. — Jno. W. 

 Taylor. 



Helix (Acanthinula) lamellata, Jeffreys, var. albina, 

 nov. var. — Shell, white or whitish. This form has been 

 noticed constantly during the last five^ years in a shadow cliff 

 (and neighbour of this) near Rya Asar (ridge) at Boras, 

 Westergotland, Sweden, by Mr. Berthold Sundler, to whom I 

 am greatly indebted for forwarding the specimens. Mr. 

 Sundler says that the albino form occurs there in great numbers, 

 while the typical is rather scarce. — Hans Schlesch, Seydis- 

 fjord, Iceland. 



The record of the abundance of Albine Acanthinula 

 lamellata is worthy of note ; such occurrences are very generally 

 accepted as one of the indications that the species thus affected 

 is nearing the limit of its geographical or altitudinal range. 

 A. lamellata stands alone amongst British species, in that the 

 animal, though possessing well developed hermaphrodite 

 glands, producing ova and spermatozoa, yet is quite without 

 the male copulatory organ in all the specimens hitherto 

 examined. Self-fertilization or the extrusion of the terminal 

 end of the free oviduct as an intromittent organ as in certain 

 slugs have been suggested as explanatory of the assumed 

 absence of the male organ. — Jno. W. Taylor. 



