222 J. G. DE Man : The Fauna of Brackish Ponds. [Voi,. II, 



and regularly tapering to the acuminate point which is slightly 

 curved inward. 



The adult L. siyli/erus, H. M, Edw., differs according to Hen- 

 derson's description {I.e., p. 439) by the following : There are 

 often two or three apical teeth on the rostrum, the lower margin 

 of which is armed with 7 — 10 teeth. The last four abdominal seg- 

 ments are dorsally more or less carinated. The distal spine on 

 the outer margin of the antennal scale is placed farther distant 

 from the apex, the distance equalling nearly one-third of the total 

 length of the outer margin. The palm of the chelae of the second 

 legs should be sulcate on its outer side, the sulcus bounded by two 

 ridges. 



The adult L. tenuipes, Hend., differs at first sight by the merus 

 of the second legs that has twice the length of the ischium and 

 that has an ill-defined sulcus on its upper surface. The apex of 

 the telson is described as blunt, but nia}^ perhaps have been worn 

 off as is often the case. The shortest of the antennular flagella 

 does not reach the end of the antennal scales. 



7, Palcemon {EupalcBmon) lamarrei, H. M. Kdw. 

 (Plate xix, fig. 4.) 



Palcemon lamarrei, H. Milne Edwards, Hist. Nat. Crustaces, ii, 



1837, P- 397- 



Nee : Palcemon lamarrei, de Haan, Fauna Japoniea, Crustacea, 



p. 171. 



Nee : Palcemon lamarrei, Ortmann, in Zool. Jahrb., v, Abth. f. 

 Syst. 1890, p. 701, taf. xlvii, fig. 2. 



Twenty-five specimens from brackish water pools at Port Can- 

 ning, Lower Bengal, collected by Dr. N. Annandale, 28 — 30th 

 January, 1906. 



Thirty-nine specimens from Calcutta (Museum tank, fresh 

 water), collected 19th December, 1906. 



These specimens, though very numerous, are all young, the 

 largest specimen from Port Canning being 38*5 mm. long from tip 

 of rostrum to end of telson ; the largest individual from Calcutta 

 is 30'5 mm. long, the rest are all of a smaller size. The fact that 

 no adult specimens have been gathered is so much the more to be 

 regretted, because they apparently belong to Pal. lamarrei, M. 

 Edw., a species which since its first description does no more ap- 

 pear in literature or has been misunderstood. 



I have already pointed out ('' ' Notes from the I^eyden Museum," 

 i, 1879, P- 166) "that a .species described by de Haan as Pal. 

 lamarrei was identical with Pal. amazonicus , Heller , from vSouth Amer- 

 ica, but the existence of this species in Japan has not been coii- 

 firmed as far as I am aware. 



Without any ground Dr. Ortmann {I.e.) declared the localities 

 mentioned by Milne Edwards and by de Haan as false, and, there- 

 fore^ described Heller's species under the name of Pal. lamarrei. 



