248 



K. NAKAZAYVA : 



leg always with a less number of propoditc joints than in other legs. 

 Outer branch of fourth pleopod (fig. 25) with the proximal joint about 

 seven times as long as the distal joint, and the latter about one-fourth 

 as long as terminal filaments. Telson elongate, triangular with 30-35 

 uniform spines on each lateral margin ; the tip rather acute, provided 

 with four spines of which the lateral two are longer than the median 

 two or other marginal spines. Both branches of uropods longer than 

 telson ; the inner branch with a group of densely packed spinules, 

 25-37 m number, situated near the inner margin just below the large 

 otocyst. Larger individuals of the species reach 16 mm. in length. 



Localities. Brackish waters of the Pacific coast of Japan. 



The material in my hand hail from Teisanbori, a canal near Sendai ; 

 the Gulf of Tokyo, near the mouth of River Kiso, Prov. Ise ; the 

 Kojima Gulf in the Inland Sea. In all these localities the species is 

 caught by fisherman in quantities almost at all seasons of the year. 



Notes. — This species is closely allied to IV. vu /gar is, but the rounded rostrum and 

 different proportional lengths of the joints of fourth pleopod in male, should serve to 

 easily distinguish the two species. 



2. Neomysis nigra h. sp. 

 Plate VIII., figs. 3, 17, 30. 



Diagnosis. Carapace with pointed rostrum. Eye reniform 



(fig. 3). Antennal scale 8-9 times as long as broad. Thoracic legs 

 moderately slender, with basal joint well developed and with propodite 

 segmented into 3-6 joints ; last leg with a greater number of joints 

 than the two legs preceding (füg. 17). Outerbranch of fourth pleopod 

 in male reaching to middle of telson, its proximal joint about 4 times 

 as long as the distal, the latter shorter than terminal filaments. Telson 

 (fig. 30) shorter than twice the breadth at base, armed with 16-20 

 uniform spines on each lateral margin ; apex truncate, rather wide 

 and armed with four spines, of which the two lateral are longer than 

 the two median as in N. japonica. Inner branch of uropods provided 



