304 
ZOOLOGY OF THE FAR EAST. 
well as in the Yangste valley. This genus has a remarkable but perhaps superficial 
resemblance to certain forms {Tylopoma) from the later Tertiary of eastern Europe 
and usually assigned to the Viviparidae. 
Systematic Description of the CoIvI^ection. 
GASTROPODA. 
Family LIMNAEIDAE. 
This family is represented in our collection from the Tai-Hu by two species only, 
one of Limnaea and one of Planorbis. The latter belongs to the section Gyraulus. 
Genus Limnaea, Draparnaud. 
Limnaea clessini, Neumayr. 
1887. Limnaeus clessini, Neumayr, Siissw .-M oil . , in Wiss. Ergehn. Reise Bela Szechenyi, 
II, p. 657, pi. iv, figs. 4-5. 
Specimens from the Tai-Hu and Soochow agree in every respect with Neumayr' s 
fig- 5- 
The species is common among weeds in the Tai-Hu and in canals at Soochow. It 
was described from the southern limits of the Gobi desert. 
Genus Planorbis, Guettard. 
Planorbis saigonensis, Crosse & Fischer. 
1863. Planorbis saigonensis , Crosse and Fischer, Journ. Conch., XI, p. 362, pi. xiii, fig. 7. 
1866. Planorbis saigonensis. Clessin. Limnneiden in Chemnitz's Conch.-Cab., ed. Kiister, p. igi, 
pi. xxix, fig. 3. 
1909. Planorbis saigonensis, Germain, Rec. Ind. Mtis., Ill, p. 117. 
Shells from the Tai-Hu agree well with Crosse and Fischer's original description 
and figures except that they have a yellowish tinge and are translucent. They are 
not more than 5 mm. in diameter. The original figure seems to have been drawn 
from a dead shell. 
We found the species in considerable abundance on the lower surface of stones at 
the edge of the Tai-Hu and among weeds in a canal at Soochow. It has a very wide 
geographical range, which extends, according to Germain, not only over a great part 
of continental Asia but also to Japan and the Malay Archipelago. It is one of our 
commonest freshwater molluscs in India, while it has been generally known under the 
name P.compressus. For the synonomy see Germain, op. cit., p. 117. 
Family MELANIIDAE. 
Genus Melania, Lamarck. 
Melania cancellata, Benson. 
1842. Melania cancellata, Benson, Ann. Mag. Nat Hist., IX, p. 498. 
1856. Melania ningpoensis. Lea, Proc. Ac. Nat. Sci. Philadelphia, VIII, p. 144. 
1882. Melania cancellata, Heude, Mem. Hist. Nat. Emp. Chinois, I, Moll d'Eau douce, p. 167, 
pi. xli. fig. 31, pi. xliii, figs. 3, 4. 
