ON A NEW EPICARIDAN ISOPOD. 



525 



Pleopod of the fouth pair, 





Length including stalk. 



Width. 



One of the plates 

 The other plate 



0,801 mm. 

 0,783 mm. 



0,400 mm. 

 0,491 mm. 



No uropod exists. Sometimes, but not always, two or four knob-like 

 tubercles are observed near tip of the distalmost segment, which 

 tubercles were considered by Sars to be the rudiments of uropods. 15 



2. Adult male. 



The adult male has thick body of an oblong outline, usually 

 somewhat convex dorsally and concave ventral ly. It is of a whitish 

 colour. Measurements of a male taken from the female specimen B, 

 as follows : 



Length of cepalon, 0,255 mm - 



Length of mesosome, 1,474 mm. 



Length of metasome, 0,692 mm. 



Greatest width of body, 0,855 mm. 

 The cephalon is somewhat halfmoon-shaped. There exists on the 

 dorsal surface a pair of distinct but irregularly outlined eyes, widely 

 apart from each other and situated near the posterior margin of cephalon. 

 In one specimen I have observed a pair of small and shallow depres- 

 sions situated near the middle of the dorsal surface of cephalon ; 

 each of them presented a somewhat reniform shape measuring 72// in 

 length and lying obliquely so as to be nearly parallel with the side 

 of cephalon. 



The antennae are short and usually hidden under the cephalon, 

 except the tips of the second pair. The very short first antennae are 

 composed of three joints. The second are slightly longer, and consist 



I) loc. cit. p. 209. 



