K. KISHINOUYE : 



sixth somite is very long, being a little longer than the length of any two 

 of the preceding somites. The lateral margins of the five anterior somites 

 of the pleon are peculiarly notched. 



The pleopods are longer and more slender anteriori}-, and posteriorly 

 become shorter and more compressed. The first pair in the female is 

 single-branched ; all the others are biramose. In the male, the peduncle 

 of the first pleopoda carries a complicated pctasma. The outer and inner 

 laminae of this are almost separated from each other. The former has 

 entire margin, while the latter is divided into two lobes near the anterior 

 end. The inner, longer lobe is rounded, and is armed with claw like, 

 horny spines at the anterior extremity. The outer, smaller lobe gradually 

 tapers to a point. The pctasma is not united at the median line with its 

 mate of the other side. The second pair of pleopoda in the male has a 

 thick and specialized part at the base of the endopodite. The sixth pair 

 of pleopoda, or the outer plates of the rhipidura, is much longer than 

 the telson. 



The telson is of about half the length of the sixth pleopoda. The 

 posterior end is blunt, and is armed with a pair of small teeth. The 

 upper half of the telson is somewhat rectangular. The lower half is 

 triangular and is bordered with ciliated hairs. 



The branchial system is just the same as that of Acctcs americanus 

 described by Ortmaxn.* 



The color of the animal is slightly pinkish. The ophthalmopod 

 shows a few yellow chromatophores. The flagella of the second antenna; 

 are pinkish. The sixth pleopoda have two pairs of bright reddish spots, 

 one on the inner side of the peduncle and the other on the outer side of 

 the endopodite. 



The size of the animal is about 20 mm 



The species is found very abundantly on muddy flats in the Inland 

 Sea, in Kiüshü and in Korea ; f. i., the Bay of Ariake, the Bay of Kojima, 



* Ortmann. — Decapoden and Schizopoden der Plankton-Expedition. 1893. P- 39- 



