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BULLETIN OF THE NATURAL HISTORY SOCIETY. 
hundred dollars, and another of similar shape in St. John for 
the same price.” These, of course, are very exceptional 
instances, the great majority of those found being small, of 
poor shape and of bad color. It must be borne in mind, in 
considering these facts, that a great amount of persevering 
labor and considerable skill is required to obtain such results. 
Its returns are too uncertain to allow the fishery ever to be of 
much economic value. 
Works of Reference. 
Pearls. By F, W. Rudler. Encyclopaedia Britannica, 9th 
Ed., Vol. XVIII., pp. 446-448. 
Pearls and Pearl-fisheries. By W. H. Dali. American. 
Naturalist, Vol. XVII., 1883. 
18. Cardium Islandicum Linnaeus, 
6 ardiurn ciliatum Fabr. 
Cockle. 
[ Cardium , heart-shaped; Islandicum, Icelandic]. 
Distribution, (a) General ; — Near low-water mark to 
fifty fathoms. Cape Cod to Greenland, and circumpolar. 
Northern Europe, Behring’s Straits, Japan. 
( b ) In Acadia ; — (in N. B.) Grand Manan, twenty to forty 
fathoms, mud, Stimpson. Rather abundant in sheltered 
places, also found in Friar’s Cove. (In N, S.) Annapolis 
Basin, rare, Verlcruzen. Halifax Harbor, Willis and Jones. 
Not reported from Prince Edward Island nor southern part 
of the Gulf. Probably occurs in mud and fine sand in many 
places in the Bay of Fundy and on the Atlantic coast of Nova 
Scotia. 
Habits. This is a very well-marked species, and, except in its 
young stages, cannot be confounded with any other on our coast. The 
valves are of a rounded form, and very convex or much hollowed out. 
On each, radiating fan-like from near the hinge, are about thirty-six 
raised angular ribs, which, on the free edge, give the shell a scalloped 
or crenulated appearance. The epidermis frequently rises into a bristly 
fringe on their summits, especially in young specimens, and this, with 
