PALAEMON MAYOTIENSIS. 173 



teeth ( ) , but especially in the variable shape of the 



second pair of legs. But the palm of these legs is always 

 at every age longer than the wrist or the fingers. 



Palaemon mayottensis Hoffra. 



Hoffman , Crustaces de Madagascar , p. 32 , pi. IX , 

 fig. 61 and 62. 



Nine specimens of this interesting form have been col- 

 lected by Mrs. Pollen and van Dam at the island of 

 Mayotte , situated west of Madagascar. By comparing 

 these specimens with those of the island of Reunion , 

 identified by me with Palaemon ornatus Oliv., as well 

 as with Indian examples of the latter species , I have 

 been led to the conclusion that the Pal. mayottensis 

 Hoffm. too should he considered only as a local variety 

 of Pal. ornatus Oliv. The only essential difference is 

 that in Pal. mayottensis Hoffm. the whole legs of the 

 second pair are always shorter in proportion to the 

 length of the body than in the typical specimens of 

 Pal. ornatus Oliv., but the proportions of the measures 

 of the various joints of these legs are quite the same in 

 Pal. mayottensis Hoffm. as in Pal. ornatus Oliv. Thus , in 

 the largest male specimen , of which Hoffmann makes 

 mention, that has a length of 125 mm., the second pair 

 of legs are only 120 mm. long; but they are much longer 

 in a specimen of Pal, ornatus Oliv. of the same size. In 

 a male of the length of 70 mm., these legs measure 50 mm.; 

 in a female of 100 mm. they attain the length of 65 mm. 

 The rostrum reaches to the end of the peduncle of the 

 internal antennae , or is somewhat longer in other indivi- 

 duals; it is armed with 8 — 9 teeth on the upper , and with 

 two or three on the inferior margin. 



Notes from the Leyden JVIuseum. 



