17G PALAEMON NIPPONENSIS. 



of the internal antennae , in others to the apex of the 

 antennal scale; the last tooth (on the cephalothorax) is 

 situated at a greater distance from the preceding which 

 extend all along the upper margin which is not curved 

 upward. The second pair of legs are equal in size and are 

 longer than the body in adult specimens , but shorter in the 

 young. — In a male of a length of 100 mm., they measure 

 125 mm., the arm being 23 mm. long, the wrist 35mm., 

 the palm 26 mm., and the hairy fingers 22 mm. — Another 

 male, measuring 75 mm.; has the second pair of legs 

 70 mm. long, the arm measuring 14 mm., the carpopodite 

 19 mm., the palm 15 mm., and the fingers 10 mm. In 

 a female, of a length of 77 mm., (I have found the female 

 specimens together with the males in the same jar , though 

 they were unknown to de Haan) the second pair of legs 

 measure 50 mm., the arm O^/o mm., the wrist 13'/2 mm., 

 the palm O^/g mm., the fingers 6^/3 mm. — In the male 

 the inner margins of the fingers of the second pair of legs 

 are provided at every age with innumerable stiff hairs , and 

 with a very small tooth at the base ; in the female these 

 stiff hairs are less numerous and more scattered. In the 

 adult male of the length of 100 mm., the arms of the 

 second pair of legs extend beyond the scale of the external 

 antennae, but in specimens of 75 mm. they are shorter 

 than the antennal scale, especially in the female. In some 

 individuals the surface of the cephalothorax is a little gra- 

 nulated , but in other specimens it is quite smooth. 



Palaemon Sinensis Heller belongs positively to this spe- 

 cies , being a young specimen of it ; the description of that 

 species , given by Heller and von Martens , agrees en- 

 tirely with that of young individuals of Pal. nipponensis 

 De Haan. — Pal. nipponensis De Haan may be distin- 

 guished from Pal. longipes De Haan by the more numerous 

 teeth on the rostrum and by the second pair of legs being 

 shorter and otherwise shaped. 



Notes from the Leyden Mnseutn. 



