The Relation of Mollusks to Fish in Oneida Lake 243 
Cerearia urbanensis Cort. Host Physa gyrina. 
. : ee In liver. 
inhabilis Cort. “  Planorbis trivolvis. 
; ‘ In liver. 
: diastropha Cort. “ — Planorbis trivolvis. 
~ In liver. 
megalura Cort. “— Pleurocera eclevatum. 
In liver. 
9 trivolvis Cort. “  Planorbis trivolvis. 
In liver and body cavity. 
Campeloma decisum.* 
4 : In liver and body cavity. 
reflere Cort. “  Lymnea reflexa. 
In liver and body cavity. 
Campeloma decisum.* 
In tissues of body above 
and at bases of gills. 
rubra Cort. 
trigonura Cort. 
“  douthitti Cort. “  Lymnea reflexa. 
In liver. 
“ asocotylea Cort. “ Planorbis trivolvis. 
In liver. 
5 polyadena Cort. “  Lymnea reflexa. 
In liver. 
4 hemilophura Cort. “ — Physa gyrina. 
In body. 
Campeloma decisum.* 
In tissue above gills. 
Physa anatina. 
In liver. 
leptacantha Cort. 
¢ brevicaeca Cort. 
This is a most excellent paper and should be read by every 
conchologist. Fourteen species of cercariz are noted infest- 
ing six species of snails. Other species of snails are doubt- 
less affected in the same manner and it is probable that few 
species are exampt. The part of the snail affected was usu- 
*We wish to call attention to the practice of many biologists of using 
molluscan material which has not been critically examined by com- 
petent conchologists. The study o° the Mollusca has now become so 
complicated, and the old species broken up into so many new species and 
forms, and so many old species have been critically examined and 
assigned to new groups, that it is unsafe to use material that has not 
been passed upon by some experienced conchologist. The species re- 
corded as Campeloma subsolidum, from Hartford, Conn. (Cort, 1915, 
pages 37, 40, 44, 46, 59) is Campeloma decisum. Subsolidum is a 
Mississippi Valley species not found in the Atlantic drainage. The 
writer is quite familiar with the region about Hartford having made 
collections in the vicinity and the only species of Campeloma there is 
decisum. 
