52 
Brit., vol. 2, p. 373, pi. 16, fig. 3. L. Limosa. Flem- 
Brit. An., p. 275. L. P. Gray’s Turt., p. 233, pi. 9? 
fig. 101. Common. 
L. PALUSTRIS. Helix P. Turt. Lin. H. Stagnalis, var- 
Pen. Brit. Zo., vol. 4, pi. 86. fig. 136. B. H. P. Mont- 
Test. Brit., vol. 2, p. 370, pi. 16, fig. 10. Flem. Brit- 
An., p. 274. Gray’s Turt., p. 239, pi. 9, fig. 107. 
common. 
* TRUNCATULUS. Helix Fossaria. Mont. Test. Brit-? 
vol. 2, p. 372, pi. 16, fig. 9. L. F. Flem. Brit. Am? 
p. 274. L. T. Gray’s Turt., p. 240, pi. 9, fig. 10»- 
Irregularly distributed. Montagu found it “upon the top 
of one of the highest hills in Cornwall, at the verge ot » 
spring near the Lizard, where no other species of sbel 
was to be found ”. 
L. GLABER. Helix Octona. Pen. Brit. Zo., vol. *' 
pi. 86, fig. 135. H. Octanfracta. Mont. Test. Brit-? 
vol. 2, p. 396, pi. 11, fig. 8. L. Octona. Flem. Brit. An-? 
p. 274. L. G. Gray’s Turt., p. 242, pi. 9, fig. 1°"’ 
The indefatigable Montagu says, “ we have found it onb 
in one part, of England, a splashy place by the road sio 0 
(a muddy pool by the side of the high road on the top 0 
a hill) half way between Fowey and Looe in Cornwal ? 
where they were plentiful in all stages of growth ; t ll „ 
young are less slender, and have only five or six volutions- 
Such however have been the changes effected within th® 
space of forty years, that I have hitherto failed in d ,s ' 
covering these shells. 
PLANORBIS. 
GENERIC CHARACTER: The shell discoidal, spi r ® 
depressed, and all the whorls appearing above and beneath' 
aperture oblong, lunate, distant from the axis ; cavW 
simple; margin not reflexed. 
P. MARGINATUS. Helix Complanata. Turt. Lin. r ,‘ 
Planorbis. Pen. Brit. Zo., vol. 4, pi. 83, fig. 123. Borla s ® 
Nat. Hist, of Corn., pi. 28, fig. 8. H. C. Mont. ’ 
Brit., vol. 2, p. 450. P. C. Flem. Brit. An., p. j 
P. M. Gray’s Turt., p. 265, pi. 8, fig. 87. Introduce 
on the authority of Borlase. 
NERITACEA. ‘ { 
The shell, of the river or sea, flattened oval, witho^ 
Columella; left margin of the aperture resembling a n 
partition. 
NERITA. b)> 
GENERIC CHARACTER: Shell semiglobular or 
flattened below ; and without an umbilicus. Ape rl 
semicircular; the left margin flat, acute; without de 
