REPORT ON THE ISOPODA. 67 



autcniue. The sterna of the abdominal segments are prolonged into stout spines in 

 both sexes. The caudal shield is truncated at its extremity. The proximal joint of the 

 anterior abdominal appendages is narrow, and, as in Set'olis schythei, the basal triangular 

 process furnished with branched hairs is aljscnt ; the suture on the operculum is at right 

 angles to the long axis of the body. The palp of the maxillipede has this peculiarity, 

 tliat tlie second joint, instead of being cordate in shape, has the two margins curved 

 inwards and parallel with each other. 



This assemblage of characters is very distinctive of all the Australian species with the 

 sole exception of Serolis mimtta ; this latter appears to be intermediate between the 

 other Australian species and the more typical species of Serolis such as Sei'olis paradoxa; 

 in the characters of the last thoracic segments, as above stated, it more closely resembles 

 the former, while in other respects it comes nearer to the latter; it would be difficult to 

 classify it definitely with either ; for this reason, and also considering the compactness in 

 other respects of the genus, it appears to me inadvisable to divide Serolis into two 

 sejiarate genera or subgenera. 



11. Serolis tuhercidata, Grube (PI. VI. figs. 1, 2). 



Serolis tuhercidata, Grube, Arcliiv f. Naturgesch., 1875, p. 227. 



The Challenger obtained two specimens of a small species of Serolis, which I identify 

 with Grube's Serolis tuherculata ; one of these specimens is a male, the other a female ; 

 they were obtained from different localities, the male from Station 161, the female from 

 Station 162 ; tlie former specimen is unfortunately much damaged. 



The female is larger than the male — it measures 19 mm. long by 17 mm. lu-oad ; the 

 length of the male is 12 mm., its breadth about the same. It appears therefore that the 

 males of this species, if not smaller than the females, are broader in proportion to their 

 length, as is generally the case in this genus. The colour of the two specimens is rather 

 different ; the female is pale yellowish brown, with innumerable black dots ; on the 

 outside of each epimeron is a larger black spot ; the male is of a uniform Init darker 

 brown. 



I have but little to add to Grube's excellent description of this species ; in my 

 specimens the epimera are not so closely applied together as he describes, and this is 

 especially the case in the male, where the points of all the epimera project freely. 

 On the cephalic shield between and in front of the eyes is a semicircular ridge of the 

 integument ; the convexity is directed forwards, and the two lateral ends are prolonged 

 backwards into two short spines; the lateral tubercles on the thoracic segments are eight 

 or nine in number on either side, and are situated on a low ridge which commences near 

 the junction of the tergal portion of the segment with its epimeral portion, and terminate 

 a little before the middle of the segment ; this ridge is longer in the third free thoracic 



