246 
ZOOLOGY OF THE FAR EAST. 
Biwa. It is said to enter the lake itself, but Dr. Annandale could find no specimens 
there. In wet weather it often travels a considerable distance from water and one 
individual was found in the streets of Otsu. The precise localities of the specimens 
are (i) from hill streams and garden paths near Otsu ; (ii) from irrigation channels at 
Hikone on the western shore of L. Biwa ; (iii) from hill streams above Sakamoto on 
the eastern shore of L. Biwa ; (iv) from a small lake at Komatsu on the same shore of 
the lake. 
In the largest male, a specimen with carapace 30 mm. in breadth, the right chela 
is enormously enlarged, 31-5 mm. in length, with very widely gaping fingers. 
Subfamily GECARCINUCINAE . 
Genus Paratelphusa, Milne-Edwards. 
1910. Paratelphusa, Alcock, Cat. Indian Decap. Crust., I, fasc. ii, p. 70. 
Subgenus Paratelphusa, Wood-Mason. 
Paratelphusa (Paratelphusa) tridentata, Milne-Edwards. 
1905. Potamon {Paratelphusa) tridentatus, Rathbun, Nouv. Arch. Mm. Paris (4), VII, p. 234, 
pi. xi, fig. 2. 
A number of distinct species were at one time confounded under this name : the 
series so labelled in the Indian Museum collection contains, in addition to the true 
P. tridentata, examples of P. convexa, de Man, P. maculata, de Man and P. oxygona, 
Nobili. In determining this material I have derived much assistance from de Man's 
papers, particularly that published in 1879,' as well as from Miss Rathbun's key and 
full references to the literature. 
The specimens of P. tridentata in the present collection are five in number, all 
collected by the late Dr. W. C. Hossack in Java. There are three males and a female 
from Buitenzorg Gardens, alt. 300 ft., and one female from Garoet, alt. 3000 ft. The 
carapace of the largest individual, a female, is 42 mm. in breadth. 
The species is recorded from Borneo, Java, Sumatra and the neighbouring islands. 
Paratelphusa (Paratelphusa) convexa, de Man 
1905. Potamon (Paratelphusa) convexus, Rathbun, Nouv. Arch. Mus. Paris (4), VII, p. 237. 
Three specimens were obtained by Dr. Hossack in Java in company with ex- 
amples of the preceding species. A male and female with carapace respectively 27 
and 28 5 mm. in breadth were found in Buitenzorg Gardens and a female of similar 
size at Garoet. The specimen from the latter locality differs from the others in 
colour, being rather closely mottled with deep purple on a dull olive ground. 
P. convexa is known from Timor, New Guinea, Borneo, Java and Nias. 
• De Man, Notes Roy. Zool. Mus. Leyden, I, p. 6i (1879). 
