REPORT ON THE ISOPODA. 139 



The adult Praniza measures about 12 mm. iu length ; the colour is whitish, and the 

 integuments are thin and translucent, besides being smooth and free from the sculpturing 

 which ornaments the body of the male. 



The head is triangular in outline owing to the projection of the mouth appendages, 

 which converge to a point some way in front of the anterior margin of the head itself ; 

 the latter is straight and slightly in advance of the articulation of the antennae. The 

 eyes are large, oval, and occupy the sides of the head. 



The first segment of the thorax is smaller than either of the two following, but it is 

 not so rudimentary as in the male. The two following segments are subequal, with 

 rounded lateral margins. 



The three next segments are completely fused together and form a swollen area as in 

 other species of this genus ; the integument is thin and but little calcified, with the 

 exception of an oval plate closely applied to the third segment, and three lateral hard pieces, 

 to which are articulated the three pairs of appendages belonging to these segments. 



The abdominal segments have their epimera compressed, and as it were tucked away 

 under the body, as in the male. 



The thoracic limbs are more slender than in the males. 



Station 149h, off Cumberland Bay, Kerguelen, January 29, 1874 ; depth, 127 fathoms ; 

 volcanic mud. 



Anceus tuberculosus, F. E. Beddard (PL X. figs. 8-12; PI. XVIII. fig. 12). 



Anceus tuberculosus, F. E. Beddard, Proc. Zool. Soc. Lond., 1886, pt. i. p. 120. 



A second species of Anceus, dredged at Kerguelen, cannot be confounded with 

 Anceus gigas. 



It is represented by two males and one female, the largest (male) specimen measures 

 only 5 mm. in length. The two male specimens differ slightly from each other, more 

 particularly in colour, but they are evidently referable to one and the same species. 



The head is prolonged in the middle line into a short rostrum, which is squarish and 

 truncated in form, with a slightly concave anterior extremity; for a short space on either 

 side of the rostrum the anterior margin of the head is quite straight ; it then slopes 

 backwards and forms a jutting projection in front of the eyes ; the dorsal surface of the 

 head is very convex behind and flattened, sloping downwards and forwards in front ; the 

 posterior convexity is divided into two by a median furrow ; the dorsal surface of the 

 head, especially posteriorly, is covered by many large, roughened tubercles. The 

 posterior margin of the head is concave. 



The first free segment of the thorax, which is represented by a semicircular tergal 

 plate following the head, is covered like it with a series of tubercles, which are, however, 

 limited to the anterior convex region of the segment. 



