Crustacea Decapoda and Stomatopoda. 273 



(v) In the second peraeopods the chela is equal in length with the merus and is 

 only about two- thirds as long as the carpus. In P.varians the chela is decidedly 

 longer than the merus and only a little shorter than the carpus. 



(vi) The dact3dus of the last three peraeopods is a little longer ; that of the third 

 pair is about half as long as the propodus in P. sinensis, rather less in P. varians. 



(vii) There are more setae (9 or 10) at the apex of the telson. 



In other respects the two species appear to be in close agreement. 



The teeth on the upper border of the rostrum vary in number from 4 to 6, ' the 

 hindmost being placed on the carapace behind the level of the orbit. On the lower 

 margin there are from i to 3 teeth. - 



On the ciliated margins of the antennules and buccal appendages there are 

 numerous small cysts of a Protozoan apparently identical with that described by 

 Sollaud. 



Sixteen specimens of Palaemonetes sinensis were obtained by Dr. Annandale in the 

 vicinity of Shanghai in small ponds and ditches of fresh water. They were found in 

 the month of October in company with Caridina and young Leander modestus : none 

 of the females carry eggs.^ 



Family ALPHEIDAE. 



Genus Alpheus, Fabricius. 



Alpheus paludicola, Kemp. 



1915. Alpheus paludicola, Kemp, Mem. Ind. Mus., V, p. 303, pi. xiii, figs. 11-13. 



The only difference I am able to detect between specimens collected by Dr. Annan- 

 dale in lyower Siam and those originally described from the Chilka Lake in Orissa is 

 that the rostrum is very slender and rather longer, extending considerably beyond the 

 end of the orbital hoods. In the form of the chelae and in all other particulars there 

 is precise agreement. The eggs are 1-3 or 1-4 mm. in diameter. 



According to Dr. Annandale' s notes the specimens differed somewhat in colour 

 from those observed in the Chilka Lake, the transverse bands of pigment on the 

 abdomen being missing. They were translucent, without definite markings, but tinged, 

 owing to the presence of scattered chromatophores, with reddish brown. The eyes 

 were black and the palm and fingers of both chelae were deeply tinged with blue, 

 especially on the dorsal surface. The eggs were pale green. 



The specimens were obtained in the Tale Sap, in the channel connecting the upper 

 and lower lakes at a depth of 3I to 8 metres. They were found in a shallow layer of 

 dense mud overlying a coar.se sandy bottom and occurred in company with Upogebia 

 heterocheir . The specific gravity of the water in the channel was variable according to 

 the state of the tide, but probably does not rise much above 1-004. 



Alpheus paludicola has hitherto been found only in the Chilka Lake on the 

 Orissa coast of India. 



1 Of sixteen specimens five have 4 dorsal teeth, ten have 5 and one has 6. 



2 Of sixteen specimens seven have i inferior tooth, eight have 2 teeth and one has 3. 



3 See Addendum, p. 297. 



