Page 2 March 1980 No. 260 NEW YORK SHELL CLUB  NO?zs 
jes -- from the h = ae 
chote Wied ver tie aide. Ed described the Ce aa oF pa oat 
tions on, the boat in vivid and disheartening rain le (pata) Spent 
some time on Brazil's Abrolhos Islands, where ppscditacbabiaghe can 
easily be counted, and where the new species e — oe Fo ‘oie 
Volutes and Olives almost outnumbered them. e : art oie e 
the stark islands for Rio de Janeiro, where he again e 
” ded two new cones, which he named 
shrimp and scallop boats. Rio yiel d all of his activitiea with 
carioca and xanthocinctus. Ed covere 
Scenic photos and shell close-ups, and with a lively narration. 
Milton Werner, Recording Sec'y, 
——— 
auls before crewmen could 
A CORRECTION TO: 
A NOTE ON MELANOIDES TUBERCULATA (Muller, 1774) etc. 
Dorothy Raeihle 
(See: NYSC NOTES No. 259, pp. 6-7.) 
In last month's issue, brief observations were given on a few fresh- 
water snails collected in the Rainbow River in Florida and kept 
alive for several weeks. Two species, Melanoides tuberculata and 
Goniobasis floridensis, were kept together, as a matter of conveni- 
ence, While we were travelling. After returning to New York the 
species were separated and a search made for eggs, as young Melano- 
ides had appeared in the aquarium. Eggs were found concealed under 
clusters of sand grains that were sticking to the shells of the 
Melanoides, and these eggs were considered to be the source of the 
baby Melanoides in the aquarium. ‘The deduction was incorrect. 
Dr. Joseph Rosewater kindly sent us a note, setting the matter 
straight, and enclosed a4 reprint of a paper by Dr. Morrison on the 
Melanians.* The truth is that Melanoides tuberculata is ovovivip- 
arous, i.e. having a brood sac, located back of the neck, in which 
the eggs develop into shell-bearing, crawling embryos. This ac- 
counts for the young Melanoides which appeared in the aquarium. Dr. 
Rosewater suggested that "The eggs covered with sand grains that you 
found on its shells probably are those of the Goniobasis.™ Undoubt- 
edly, as that was the only other species in contact with the Melano- 
ides for weeks, and the egg masses are as described by Dr. Morrison. 
As for the Melanoides repopulating the swimming pond at Palm Bay 
Dr. Rosewater remarks: "The suggested parthenogenicity (no males} 
of Melanoides may account for its ease of populating new locations. 
Just one snail dumped into a lake or river with the proper condi- 
tions can start a new colony ..." 
The third species mentioned in the article last month aris 
cornuarietis, the Wheeled Apple Snail. Browsing NAUTILUS ae Teac 
that this Marisa was first found in 1957 in the Coral Gables Canal, 
at that time "the only known colony established in natural waters 
in the United States."** Its introduction? Via the aquarium trade. 
* Morrison, J. P. E., 1954. The Relationshi 
ps of Old and New World 
Melanians. Proc. U.S.N.M. Vol. 103, No. 3325, 357-394. 
**Hunt, Burton P., 1958. Introduction ‘ : 
NAUTILUS Vol. 72 (2) s3cg4,°) Marisa into Florida. 
pre me Pane e 
ie BE SURE TO READ THE ANNOUNCEMENT ON PAGE 8 ! 

