
MOLLUSCS, VERMES AND HYDROZOA 

Best AQuarium Swnaits. Experienced aquariists avail themselves 
of but four species as aquarium scavengers. hese are the Planorbes, 
usually P. ¢rivolvis, the larger common species, popularly known in the 
author’s section of the country as the ‘‘Ram’s horn” or “flat Schuylkill 
snail;’ Viviparus viviparus or ‘Potomac snail;’’ Lymnea auricularia or 
“Transparent African snail;”’ and Viviparus malleatus or “Japanese snail.” 
The first two have been already described, the latter two will now be 
mentioned. 
L. auricularia, Fig. 178, is native to the water systems of the Medi- 
terranean and some other parts of Europe. It is a beautiful snail having 
a peculiar earshaped shell with a broad body whorl and the others flattened 
and rapidly diminishing, a 
and a depressed spire. The 
shell is of a nearly trans- 
parent light horn-color, 
through which the darker 
color and the brown and 
black spots of the body 
It has broad FIG. 178. Transparent African snail, Lymn@a auricularia. 
7 
Z 
i 
YY 
My, 

plainly show. 
and flat conical tentacles, small dark eyes and a broad foot, paler on the 
under side. It feeds entirely on alge, decaying vegetation and offal, never 
attacking growing plants. It is active in habit, never comes entirely above 
the surface of the water, thrives in the aquarium and is one of its most 
interesting inmates. It is not as tenacious of life as the first two named, 
but is prolific and reaches a maximum length of 1% inches. Its eggs are 
deposited in long vermiform gelatinous masses on the stems and under 
the floating leaves of plants and on the glass of aquaria; which hatch in 
12 to 20 days, the tiny snails being almost invisible in their transparent 
shells. This snail is exotic but is extensively bred in the Eastern and 
Middle States; may sometimes be had of dealers, but is usually obtained 
by exchange or purchase among 
aquarium fanciers. 
V. malleatus, the Japanese 
snail, Fig. 179, has now become 
naturalized at San José, Califor- 
nia, in a little valley at the foot 
of Mount Hamilton. It is an 
edible snail,known to the Chinese 
as ‘“Tsen law,” which was either 
planted or accidentally intro- 
duced’ by the: Chinese and 

FIG. 179. Japanese snail. Viviparus malleatus. A 
Nearly aduit and younger shell, showing keel, Japanese of the neighborhood. 
238 
