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THE NATURAL HISTORY SURVEY. Pu | 
very small; jaw provided with an accessory plate; lingual 
membrane with ‘a high, narrow, central tooth, tricuspid; lat- 
erals of same size, bi- or tricuspid; margins with narrow bases, 
‘multicuspid. 
Genus SUCCINEA Draparnaud, 1801. 
Shell: Very thin and fragile, imperforate, ovate; -aperture 
very large, occupying the greater part of the shell; columella 
acute, simple; peristome straight, simple. 
Animal: Elongated, truncated before, pointed behind; 
Fig. 54. 
Animal of SUCCINEA OVALIS Say. (Original.) 
mantle protected by a shell, but not concealing the entire 
animal as in Helix; respiratory and anal orifices on right of 
mantle edge, just beneath the peristome; generative orifice be- 
hind right eye-peduncle; caudal mucus pore absent; locomo- 
tive disk (?) (Fig. 54). 
Faw: Arched, with large, quadrangular accessory plate; 
the ends (of jaw) acuminate or blunt; cutting edge with median 
projection, frequently broken by ends of ribs. Lingual mem- 
brane resembling that of Patula. The middle portion of the 
lower edge of the base of attachment of the central tooth is 
peculiarly cut away and thinned, as is also the inner lower 
lateral angle of the base of the laterals and marginals. The 
marginals are peculiarly constructed as regards the cusps, 
there being two small outer side cusps, each bearing cutting 
points; the reflection is quite small when compared to the size 
of the base of attachment. 
Genitalia: Mr. W.G. Binney thus describes the genitalia 
(of S. ovals): ‘The testicle is not separated into distinct fas- 
ciculi by the parenchyma of the liver, as in He/zx, but forms a 
single mass; the epididymis is very much convoluted, and ap- 
pears always to be distended with spermatic matter; the pros- 
tate gland is usually short, occupying the upper half only of 
the length of the oviduct, and is thick, clavate, and more or 
less covered by pigmentum nigrum cells upon the surface; the 
penis sac is long, cylindroid, curved downward at its upper 
