REPORT ON THE ISOPODA. 25 



A fourth specimen from Marion Island is also apparently immature. Both the new- 

 species are remarkable in certain ways ; in Munna maculata the male has evidently the 

 same form of body as the female, and is not proportionably elongated, as is the case, 

 for example, with the second species, Munna pallida ; in this latter the eyes are not 

 elevated upon appreciable stalks as they are in other species of the genus. 



Munna maculata, F. E. Becklard (PL XL fig. 14). 



Munna maculata, F. E. Beddard, Proc. Zool. Soo. Lond., 1886, pt. i. p. 98. 



A single specimen of this species, which is a male, was dredged in 28 fathoms at 

 Kerguelen. 



Although the specimen is a male it does not display the cylindrical form of body 

 which is generally characteristic of that sex, and which is the case, for example, with the 

 next species of this genus to be described. 



The present species is large as the genus goes, measuring 4 mm. in length. 



The specimen is mounted upon a slide in Canada balsam, and is remarkable for the 

 numerous black pigment spots which cover the body. 



The head is about as long as the first two segments of the thorax ; its anterior margin 

 is straight and fringed with a row of stiff branched hairs ; on either side is a deep notch 

 for the insertion of the antennules ; just behind the latter, and from the dorsal surface of 

 the head the eyes take their origin ; they are placed at the summit of a moderately long 

 stalk, which is constricted towards its base. 



The first four segments of the thorax are subequal and in every case longer than the 

 three posterior, which are also narrower and are curved backwards, as in the typical 

 members of the genus ; the thoracic segments have short rounded epimera which are 

 invisible on a dorsal view\ 



Between the thorax and the abdominal shield, as in other species of this genus and 

 in allied genera such as Pleurogonium, there is an intercalated free segment which has not 

 the lateral extension of the foregoing segments. 



The abdominal shield is oval in form, and very convex dorsally, it ends in an obtuse 

 rounded extremity. 



The antennules are about as long as the head and the first segment of the thorax 

 taken together. The two basal joints are very stout, and the two distal joints of the 

 peduncle are subecpial and extremely small ; the flagellum consists of four joints which are 

 elongated, but gradually decrease in length towards the extremity, the terminal joint 

 being very short ; the length of the entire flagellum is about equal to that of the peduncle. 



The antennas are very long, about twice the length of the whole body of the animal ; 

 the last two joints of the peduncle are very elongate, the terminal joint being the longer 

 of the two ; the flagellum is shorter than the peduncle. 



(zool. chall. exp. — part xlviii. — 1886.) Bbb i 



