DESCRIPTION OF SPECIES 285 



3. Serolis gracilis, Beddard. 



S. gracilis, Beddard, 18840, p. 332; 18846, p. 6i, pi. iii, figs. 7-13. 



Diagnostic characters. The largest male specimen in the Challenger collection 

 measures 21 mm. in length and 22 mm. in greatest breadth; the females are much 

 smaller, being 9 mm. in length and 8 mm. in greatest breadth. 



The outline of the body is almost circular and its surface is covered with scattered pits ; 

 its colour in alcohol is a dark slate-blue, varying to reddish yellow upon the terga of 

 the posterior thoracic somite and the abdominal segments : the cephalosome is strongly 

 convex between the eyes, whilst the antero-lateral areas are flat and depressed; the 

 rostrum is very short ; the eyes are small and appear to contain little or no pigment. 



The coxal plates are flat and sickle-shaped and gradually increase in length from 

 before backwards : in the male those of the seventh somite extend for some distance 

 beyond the end of the terminal segment, whilst those of the female are much shorter 

 and do not reach to its extremity. All the free thoracic somites (3-7) are separated from 

 their respective coxal plates by sutures. 



The pleural plates of the second abdominal segment are longer than those of the third ; 

 in the male they extend for a short distance beyond the end of the terminal segment, 

 whilst those of the female do not extend farther than the middle of the segment ; the 

 plates of the third segment in the male are about the same length as those of the second 

 in the female, whilst the third in the female are considerably shorter. 



The terminal segment is squarish in outline, it possesses "a slight longitudinal 

 median keel which is crossed at right angles by a sinuous ridge with three convexities, 

 one median and two lateral, which correspond to the spines on the caudal shield of 

 S. neaera, Beddard and S. schythei, Lutken ; about the end of the anterior third of the 

 caudal shield is a short flat spine in the middle line and two oblique ridges, one on either 

 side of this spine; the lateral portions of the caudal shield are bent down". 



In the male, plumose hairs are present on the inner margin of the merus and carpus 

 of the third appendage and on the merus, carpus and propodus of the last. 



Remarks. My observations agree with those of Beddard except that in his description 

 of the maxilliped he says that "the stipes and lamina are not separated by a complete 

 suture " and in his figure (pi. iii, fig. 10) this suture is also omitted. In the specimens at 

 the British Museum a suture between the basipodite and the lamella of this appendage 

 is clearly visible. 



Distribution. Off Pernambuco, South America, in 675 fathoms. 



4. Serolis paradoxa, Fabricius. 



Oniscus paradoxus, Fabricius, 1775, p. 296; 1787, p. 240. 



Cymothoa paradoxa, Fabricius, 1792-8, Suppl. pp. 304, 503. 



Serolis fabricii, Leach, 18 18, p. 340. 



Serolis orbignyi, Audouin and Milne-Edwards, 1841, p. 25. 



Serolis orbigniana, Milne-Edwards, 1840, p. 232; Grube, 1875, p. 225. 



Serolis paradoxa, Miers, 1881, p. 61 ; Beddard, 1884*, p. 33, pi. v, figs. 12-14; Nordenstam, 1933, 



PP- 51-5. text-figs. 



■nviT 5 



