BY JAMES NELSON GOWANLOCH 133 



Buccinum undatum. is a marine gastropod, attaining a length 

 of about six centimetres and with a shell grayish in colour ex- 

 hibiting six whorls. The species is distributed from low water 

 mark to a depth of at least 100 fathoms over the Atlantic, 

 Arctic and Pacific, coasts from the Atlantic coasts of North 

 America to the coasts of Siberia. In Europe where the species 

 appears to attain a larger size than in our waters, it is extensively 

 used both as food and as cod-bait. Omnivorous in diet, the 

 Common Whelk crawls about on the substratum by means of 

 its muscular foot and when confined to an aquarium it will 

 sometimes climb a few centimetres up the glass sides. Along 

 coasts with average tidal changes Buccinum approaches ex- 

 posure only during the dead low water of the spring tides. 

 Thus the individuals of the species are never exposed under 

 normal conditions to the danger of death from loss of moisture 

 during inter-tidal desiccation. 



Such, however, is not the case in the Bay of Fundy where 

 the remarkable diiferences in tidal level of from eight to ten 

 metres lay bare at one period of the month an area of the 

 littoral zone that at other periods of the month is completely 

 and even deeply submerged. Under these conditions species 

 that rarely if ever become completely exposed by tidal change 

 will through normal dispersal spread during one period of the 

 month into an area of the submerged sea-bottom that in the 

 course of the tide-cycle will at the spring phase become exposed 

 for hours to the sunlight while the tide is out. While carrying 

 out work at the Atlantic Biological Station situated at St. 

 Andrews, New Brunswick, the writer became interested in the 

 responses of Buccinum to these unusual conditions imposed 

 upon it by the Bay of Fundy tides. The results of a few pre- 

 liminary experiments proved to be so unexpected and stood so 

 apart from the usual behaviour of inter-tidal forms that a brief 

 investigation was undertaken of the normal dispersal behaviour 

 of the species and the behaviour of individuals during normal and 

 experimental exposure to desiccation. Data secured by these 

 diverse methods supported the view that we are here dealing 

 with the interesting case of an organism compelled by unusual 



