yew YORK SHELL CLUB NOTES No. 259 
February 1980 Page 
py the Rainbow River. Of course we waded t 
river bottom was generally sandy with some Che pie a 
a total of three species: Melanoides tuberculata (Muller, 1774), a 
Thiara Snail; Goniobasis floridensis Reeve, the Floridian River’ 
Horn Snail; Carbicula sp. (leana?), the pesty Asiatic Clam It 
ee ue ce aii our of the three kinds of shells we had 
icked u e introduce Asian speci 
pel Does anyone really Aw? pecies. We wondered how they got 
the Melanoides lived in their small aquarium for over a 
produced quite a few young: I kept finding young Mel bouace: oe the 
container, but it was not until we were back in New York and could 
make a really careful examination of the material that the eggs 
were located. Several of the adult shells seemed to have merely a 
daub of sand clinging to their shell. Close inspection revealed 
that these “daubs" were clusters made up of sand grains "glued" 
together. In underneath a cluster would be from three to five eggs. 
The clusters were roughly round in shape and measured from 14mm to 
2mm in diameter. I did not observe emergence from the egg case, 
but I feel safe in saying that the young snails had direct develop- 
ment within their egg capsule and emerged crawling. At any rate 
this method of reproduction would explain Karl Jacobson's observa- 
tion of the repopulation in the swimming pond at Palm Bay (see: 
"Life Revives in Old Brevard" NOTES 247.3,4; 240.3,4), the newly 
ee snails (or the egg cases) being too minute for even a duck 
to find. 
As all the shells collected on that trip have long since been given 
to collectors who specialize in freshwater mollusks, I can only 
recollect the Corbicula being a pretty little shell with a bad rep- 
utation. Variations in the shell of specimens within a colony and 
from colony to colony (sometimes due to the age of the clam) have, 
since its introduction to this country perhaps fifty years ago, 
given rise to a number of specific names that are now gradually be- 
coming part of the synonymy. The biological studies will probably 
be the deciding factor, as some groups have free-swimming larvae 
while others have non-swimming larvae. 
It was about that same time that we were shown several specimens 
of Marisa cornuarietis (Linne, 1758), the attractive Wheeled Apple 
Snail. Someone had collected a handful "from a ditch back of the 
shopping center in Fort Myers” and asked if we knew what they were. 
We didn't. This is another import, being originally a South Ameri- 
can species. AMNH GUIDE TO SHELLS (Emerson & Jacobson, 1976) on 
page 293 reports that it has been welcomed in Florida because it 
is a voracious feeder on the peas it clad “eee bee eet 
of Al Taxson's observation of grackles feeding on Marisa, 
it be that the limpkin and the everglade kite might accept it also 
as an item of diet? 

