166 PALAEMON LAMARREI. 



measures are respectively 17 mm., 13 mm., lO^/g mm. , the 

 difference between wrist and palm being already diminislied , 

 and in very large adult specimens the carpopodite and the 

 palm have the same length. 



P alaemon Lamarrei M. Edw. 



Milne Edwards, Hist. Nat. t. II, p. 397. — De Haan, 

 Fauna Japonica, Crustacea, p. 171. 



According to De Haan this species lives also in 

 Japan. — I have found in the collection of the Leyden 

 Museum the type specimen, that has been described by 

 De Haan as Palaemon Lamarrei M. Edw. A close exa- 

 mination of this species has led me to the conclusion , 

 that it is wholly identical with a species from South-America , 

 described by Heller under the name of Palaemon Ama- 

 zonicus. (Sitzungsberichte Wien. Akad. Bd. XLV , 1862, 

 p. 418, taf. IL fig. 45). 



There are many specimens of this Palaemon Amazonicus 

 Heller from Suriname in the Museum Collection, which 

 species may be distinguished from the Indian Palaemon 

 carcinus Fabr. by its much smaller size and more especially 

 by the fact that the first pair of legs are scarcely as long 

 as the scale of the external antennae (they are mostly 

 somewhat shorter) , that the second pair of legs are as long 

 as the rostrum , and that nearly the third anterior part of 

 the carpopodites of these legs projects beyond the scale of 

 the external antennae. The teeth on the upper margin 

 of the rostrum are also arranged somewhat otherwise in the 

 American species than in Pal. carcinus Fabr. : in Pal. Amazo- 

 nicus Heller there are 7 — 8 equidistant teeth on the posterior 

 convex part , only the posterior tooth of which being placed 

 behind the eyes ; these teeth are separated by a great inter- 

 val from the three or four anterior teeth which extend to 

 the apex of the rostrum ; in Palaemon carcinus Fabr., on 



Notes from the Leyden ZVIuseum. 



