Crustacea Decapoda and Stomatopoda. 271 



tion are from Kyoto and Sapporo and reach a length of about 54 mm. Miss Rathbun ' 

 has remarked that examples from the sea are larger than those from fresh water, 

 attaining a length of 6C^ mm. Dr. Annandale' s specimens from Lake Biwa are, however, 

 considerably larger than any that she examined from that locality. 



According to an excellent colour sketch, made by Dr. T. Kawamura of the Otsu 

 laboratory, living specimens are closely mottled with dull ohve green with a dark 

 posterior border to each abdominal somite. On either side of the carapace are three 

 characteristic dark lines ; two of these are on the branchiostegal wall and are nearly 

 vertical, converging a little as they approach the inferior margin ; the third extends 

 obliquely downwards and forwards from the cardiac region, running between the 

 ■two other lines at its lower end. The articulations of aU thg leg segments are tinged 

 with yellow ; there are dark patches at the base of the pleopods and at the tip of each 

 uropod there is a large pale spot bordered with purplish brown. Dr. Annandale notes 

 that specimens from bare ground, either in deep or shallow water, were almost colour- 

 less, though still retaining traces of the characteristic markings on the carapace. Ex- 

 amples with the deepest colouration were found among dense weed at a depth of 

 about 10 ft. 



The species forms one of the most important commercial products of Lake Biwa, 

 being caught near Otsu in very large numbers in small basket traps. 



De Man has given a list of the localities from which Leander pauddens has been 

 recorded. It is e\idently abundant in all parts of Japan and is known from Hokkaido 

 and the Kurile Is. Miss Rathbun has recorded it from Fusan in Korea. 



Genus Palaemonetes, Heller. 



1911. Allocaris, Sollaud, Bull. Mus. d'Hist. nat. Paris, p. 50. 



1913. Allocaris, synoinmous with Palaemonetes, Pesta, Ann. K.-K. Hofmnszums Wien, 



XXVII, p. 9. 



1914. Coiitierella, Sollaud, Bull. Soc. zool. France, XXXIX, p 318. 



A small Palaemonid, obtained by Dr. Annandale in fresh water in the vicinity of 

 Shanghai, is without doubt identical with that dascrlb^d by SDllaai u ilar the nanie 

 Allocaris sinensis. The new genus created for this species differs from Palaemonetes 

 only in two points, — the wide separation of the coxal aid basal segments of the first 

 maxillipedes and the greater number of plumose setae at the apex of the telson. 



Sollaud was apparently so impressed with the importance of these characters that 

 he regarded Allocaris sinensis as the representative of an isolated branch which 

 had evolved independently of all other Palaemonid ae. His views, however, have been 

 severely criticised by Pesta, who regards Allocaris as a synonym of Palaemonetes and 

 has even expressed the opinion that A . sinensis is nothing more than a local race of the 

 European P. varians. No two views could possibly be more divergent. 



In reference to the characters noted above, Pesta has shown that the form of the 

 first m.axillipede is very variable in Palaemonetes varians, in some cases bearing 

 an exceedingly close resembla ice to that of Allocaris, while the number of setae at the 



I Rathbun, Proc. U.S. Nat. Mus., XXVI, p 51 (1,902). 



