Hey : Shore-Collecting near Scarborough and Filey. 345 



marking-s, yellow, green, or brown, and sometimes richly banded, 

 at others reticulated with a darker colour. In the variety of 

 colour it presents it may be compared with the Helix nemoralis 

 of our lanes. 



The Dog" Whelk {Purpura lapillus) is very common between 

 tide marks. Only two reversed specimens of this shell are 

 known, and one of them was picked up years ago at Scar- 

 borough and came into Mr. Bean's possession. Not long ago 

 I received a letter from a gentleman at Flamborough saying he 

 had got a reversed specimen of the Dog Whelk. I asked him 

 to forward it by registered post, which he did. It proved, how- 

 ever, to be only a reversed specimen oi the Common Whelk 

 [Buccinutn undatum), which is far from rare. W^hy reversed 

 varieties should be common in some species and very rare in 

 others is a curious point which requires some elucidation. 



No shell is more conspicuous between tide marks than the 

 Common Limpet {Patella zmlgata), much used for bait, and 

 commonly called ' Flithers.' One species of Chiton (sometimes 

 called Sea-Woodlouse) is very common in this zone under 

 stones, Craspedochiliis cinereus. Gibbula ( = Trochus) cineraria 

 is also common in these rock pools, the shell which, after it has 

 been rubbed by the waves, appears all pearl, and is in this 

 condition often called ' silver churches.' 



The Common Starfish {Uraster rubens) and the Dog Crab 

 {Carcinas nioenas) abound in this zone. In winter the female is 

 found with a great mass of orange-coloured spawn tucked 

 under her tail. It appears as though crabs were once very 

 like lobsters, but some millions of ages ago, had received 

 a shock which had caused them to clap their tails to their 

 bellies like a frightened dog, and had kept them there ever 

 since. Sea-anemones are collected for bait at Scarborough, 

 and the fishermen give them a highly-descriptive name — ' Scar- 

 paps.' 



The next zone, disclosed only at spring-tides, mtroduces us 

 to a host of new forms. Here we find in great abundance at 

 Scarborough two species of Pholas which live in holes they 

 have excavated in the softer rocks. They are very easily 

 collected on the north shore by the aid of a chisel, as they 

 burrow in great numbers in the clays of the estuarine series 

 which there form the scars. 



Zirphcea crispata is the larger species, with very widely- 

 gaping valves. It is a northern shell and occurs in the shelly 

 patches in the Basement Boulder Clay at Bridlington. The 



1903 September i. 



