Baker — The Molluscan Fauna of McGregor, Iowa. 251 
was permitted to buy about a bushel and a half of clams for two 
dollars but was cautioned not to take a pearl, only the shells 
being salable. It was curious to see the value placed upon an 
unopened clam. Offers of three, four or five dollars for a 
small lot of freshly-caught, living clams were scornfully re- 
fused. The value placed upon distorted or diseased clams, 
called by the fishermen ‘‘cripples,’’ was fairly ludicrous. 
They have a belief that a cripple is almost always sure to con- 
tain a pearl and they are not always disappointed in this be- 
lief, for many distorted individuals do contain fine pearls. 
Two beautiful pearls were shown the writer by a resident of 
McGregor, one nearly a third of an inch in diameter and of 
exquisite luster and color, being valued at fifteen hundred 
dollars, and another smaller one at about three hundred 
dollars. These had been recently secured from the clams 
near McGregor. 
The writer believes, after a careful study of the mussel 
fishery at this place, that the large number of cripples en- 
countered is due largely to the crowfoot dredge. Many 
shells have the valves curiously distorted, as though broken 
by accident, and it seems quite probable that younz mussels 
which were broken by the hook should have grown and be- 
come distorted in consequence of the injury. The broken 
valves would also offer an effective means of commun- 
ication to the inside of the clam, and sand, the eggs of 
mollusks and parasitic animals could easily find entrance 
and produce further distortion, or, perchance, a pearl or 
two. 
A sad and suggestive feature of the mussel fishery at this 
place is the waste of shells which are of no value either for 
their shells or as containing pearls, and are thrown upon the 
shore when the catch is picked over. These consist of 
Anodonta, thin-shelled Lumpsilis, Alasmidonta and any small 
or thin-shelled clam. In some places the shore is fairly paved 
with these shells. Such wanton destruction grieves the true 
naturalist. 
It may be of interest to tabulate some of the species which 
contained the greatest amount of abnormal pearly matter and 
