290 Canadian Record of Science. 
low and warm, and the bottom is soft mud and sand, 
a large variety of Mya arenaria is very plentiful in the flats 
bare at low tide; so much so that the place is resorted to 
by fishermen from localities lower on the coast for bait. It 
sometimes attains the length of 4} inches, and has a thick, 
dense shell, without perceptible epidermis, and often with 
radiating bands. So far as I] am aware, neither Mya trun- 
cata nor the peculiar variety of MM. arenaria referred to 
below, occurs on this part of the coast. 
I have not infrequently dredged Mya truncata, usually 
the long variety, but sometimes the short Uddevalensis 
variety, in deep water outside the bay, but have not seen it 
above low-water mark, though it occurs not far from this 
line; and, on the opposite side of the River St. Lawrence, I 
have found it at Tadoussac, where the water is still colder, 
close to low-water mark. I was not aware that Mya are- 
naria occurred on the comparatively steep and stony shore 
outside the bay, and it is certainly not found there inside of 
the low-water limit. 
Last summer, however, after a heavy easterly gale, great 
numbers of Mya arenaria, in a living state, and a few speci- 
mens of M. truncata, were thrown up on the beach, and 
must have been derived from the mud disturbed by the 
breakers at no great distance outside of low-water mark, 
or on a slight bank a little further seaward. These 
shells were all of small or moderate size, somewhat round 
and flat in form, much wrinkled and covered with a thick 
brown epidermis which extended a little way beyond 
the posterior end of the shell, which was, however, rounded 
and not truncated, and destitute of the corneous tube of 
M. truncata. Still, many of the specimens might, at first 
sight have been mistaken for M. truncata, with the tube 
partly broken off. This enabled me, for the first time, to 
understand the remark of Fabricius, that in Greenland the 
two species are so similar, that but for the hinge and the 
tube they might be confounded. With these were thrown 
up specimens of M. truncata, which must have lived with 
the others, the inner limit of MM. truncata probably overlap- 
