48 
ZOOLOGY OF THE FAR EAST. 
Cristaria plicata (I/each). 
(PI. Ill, figs. 7, 8.) 
1879. Dipsas plicata (s.s.), Kobelt, op. cit., p. 429, pi. xvi ; pi. xviii, fig. i. 
1879. Dipsas plicatus, Heude, Conch. Fluv. Nanking V, pis. xxxiii, xxxiv. 
The species has a considerable synonomy (see Simpson, op. cit.) and appears, to 
judge from Heude 's plates in the Conch. Fluv. Nanking, to reach a larger size in parts 
of China ' than it does in Lake Biwa. In Japan it is often confused with H. herculea, 
which does not occur there, and with C. spatiosa and Pletholophus reiniana. Kobelt's 
pi. xvii represents C. spatiosa. 
The shell of C. plicata undergoes considerable changes in form in the course of its 
growth. Adult and half-grown specimens are well figured by Kobelt on his plates 
xvi and xviii ; photographs of still younger shells are reproduced (natural size) on pi. 
Ill, figs. 7, 8 of this paper. Young individuals were dredged from a depth of over 40 
fathoms, but were also found in 5 fathoms. 
C. plicata has a wide range in north-eastern Asia and occurs also in Cambodia. 
It is common in Japan, where it is fished for its pearls and as food. 
Cristaria spatiosa (Clessin). 
1879. Dipsas plicata var. japonica, Kobelt, op. cit., p. 431, pi. xvii. 
1900. Cristaria spatiosa, Simpson, op. cit., p. 584. 
This species seems to be less common in Lake Biwa than C. plicata. We obtained 
several specimens from a large pool at Komatsu on the western shore of the lake. It 
is probably a shallow- water form and is only known from Japan. 
Genus Pletholophus, Simpson. 
1900. Pletholophus (subgenus of Cristaria), Simpson, op. cit., p. 585. 
This group of species is regarded by Simpson as a subgenus of Cristaria, but is 
distinguished by the vestigial hinge- teeth of its shell. The species occur in Cambodia, 
Tonkin, China, Formosa and Japan. 
Pletholophus reiniana (v. Martens). 
1875. Cristaria reiniana, v. Martens, Jb. d. Malak. Ges. II, p. 136, pi. iii, fig. i. 
1900. Cristaria reiniana, Simpson, op. cit., p. 585. 
It is doubtful whether Kobelt's description and figures {op. cit., p. 432, pi. xii, 
fig- 4'} pl- xxii, fig. 2) represent this species. My own shells are relatively much 
broader; superficially they are not unlike those of Cristaria spatiosa. They are from 
a pool at Komatsu. The true P. reiniana is found only in Japan. 
Genus Anodonta, Lamarck. 
1900. .Anodonta, Simpson, op. cit., p. 620. 
The genus (s. I.) is widely distributed in the Palaearctic and Nearctic Regions. 
A few species penetrate into the outlying districts of the Oriental Region, but none 
' Shells are used in the neighbourhood of Soochow as bailers in fishing-boats. 
