164 The Irish Naturalist. [July, 



number of years past about 60 to 100 per annum seem to have 

 been found, with one or two "spiders" as I have heard the 

 scalariform shells called at Bundoran. 



In addition, some rather interesting " repairs " occur (Fig. 

 8), also specimens having a considerable rough extension to 

 the otherwise complete lip (Figs. 10 and 11), and an occasional 

 reversed form wdth a tendency to the scalariform shape (Fig. 

 7). The majority of the latter are however lower in the spire 

 than the common dextral form. Some of the last are very 

 high in the spire, wdth deep suture, and I have seen ten 

 specimens distinctl}^ scalariform ; a few of these are in the 

 Dublin Museum. One or tw^o were fairly fresh young 

 specimens. These are, I take it, merely monstrosities wiiich 

 occur oftener here than elsewhere. Of the reversals, on the 

 contrary, were they a distinct race now extinct rather than 

 mere "sports"? Their numbers seem to favour the former 

 idea, and I have never seen a really fresh specimen, or one with 

 epidermis on. A few^ show the banding as clearly as frCvSh 

 shells, but this (as witness the well-known Dog's Bay finds) 

 may be the case even though they have been buried in dunes 

 for ages. The}^ are of fair size, and, on the whole, wxigli more, 

 when not sand-eroded, than the typical living specimens. 



On one of my visits to Bundoran, while hunting for " shell 

 pockets " I found living on a small area of the dunes a thick 

 heavy form of var. hyalozonata (Fig. 9) with the white lip w^hich 

 accompanies that variety. The pale yellow epidermis is very 

 thin and hardly a trace of it remains by the time the shell is 

 completed. This, wherever else I have collected it, has 

 always been a much lighter shell than the type of the locality 

 where it occurred, and this is also the experience of friends 

 who have given special attention to this species ; by type of 

 course I mean the ordinary banded and unhanded forms with 

 dark lip. At Bundoran, on the contrary, many of the shells 

 of hyalozonata, though smaller than the type there, are thicker 

 and heavier, so much so, that three or four of the heaviest 

 weigh almost as much in proportion to their size as the average 

 heavy sub-fossil specimens from Dog's Ba}-, Co. Galwa}^ Four 

 specimens w^eighed respectively 50, 42, 30, and 27 grains, 

 average 37, a high average even when compared with the 

 heaviest typical shells, 



