1g10.| J. R. HENDERSON & G. Marruar: Freshwater Prawns, 301 
and the two preceding. The chelipedes are much weaker than in 
P. scabriculus and P. dolichodactylus, while the longer chelipede is 
a little shorter than the body. The setose hairs on the chelipedes 
are short and few; those on the palm and bases of the fingers are 
comparatively sparse, so that the joints appear almost naked. 
The spinules on the chelipedes are feebly developed. The carpus 
is always shorter than the merus. The palm is not so strongly 
compressed as in P. scabriculus and P. dolichodactylus, with the 
result that it is much longer than broad, the proportion being 
four to one; it is wider than the distal end of the carpus, and 
much longer than the fingers. The fingers which are equal are 
considerably thinner and their tips are much less strongly incurved 
than in the other two species; the tubercles on the fingers are 
considerably smaller and fewer: there being only from 12 to 18 
on the mobile finger and I1 to 15 on the immobile. 
The measurements given on page 304 are taken from the large 
chelipedes of certain individuals which we regard as adult. 
It will be seen from the measurements that there is less varia- 
tion in the joint-lengths of the chelipedes in the present form than 
in P. scabriculus and P. dolichodactylus. 
We give on page 305 the joint measurements of three specimens 
which we are unable to satisfactorily assign to one or other form 
but which appear to connect P. scabriculus and P. dubius. 
Colours when fresh.—In the males of P. dubius there is a median 
dorsal pale band as in P. scabriculus. The fingers of the shorter 
chelipede are doubly banded with blue as in the females of 
P. scabriculus; those of the larger chelipede are dark blue, with 
the extreme tips almost white. 
Localities.—-A large series from Walajabad, Saidapet and other 
localities in the Chingleput District. 
Note.—Though we have allowed the last three forms to re- 
main distinct, the following considerations strongly incline us to 
the view that they may all belong to one and the seme species. 
Adult males of P. scabriculus and P. dolichodactylus were found 
living together at Walajabad, Red Hills and Saidapet, and all three 
forms were obtained from the same tanks at Palghat and Walaja- 
bad, while young males obtained along with them were all alike. 
All the female specimens collected under the same conditions were 
also identical. Finally we possess specimens which we are forced 
to regard as connecting links between the three types of male. 
ADDENDUM. 
Since the previous pages were written we have received from 
Villivakkam, a village in the neighbourhood of Madras, an addi- 
tion to our list in the species which de Man, from an examination 
of Bengal specimens (Records, Indian Museum, vol. i, part 3, 
p. 222, 1908), has identified as P. lamarrei, Milne-Edw. Many of 
the specimens are females with ova, measuring from 40 mm. to 
45 mm. in total length, and the eggs, which are unusually large 
