REPORT ON THE ISOPODA. 33 



genus, on account of its occurrence so far north as California, has been briefly char- 

 acterised by Lockington ^ as follows : — " Thorax and abdomen conspicuously keeled upon 

 the centre of every segment ; the first segment slightly waved on its posterior margin, 

 the curve of the segments increasing rapidly in such a manner that the last entirely 

 encloses the free abdominal segments on their sides. Caudal segment rounded at the 

 extremity, with two marginal teeth on each side at a considerable distance from the 

 extremity, the central carina running the entire length of the segment ; last basal joint 

 of inner antennae longer than the flagelhmi ; flagellum of outer antenuse much shorter 

 than either of the two of the preceding basal joints, and last basal joint about equal in 

 length to the penultimate. Eyes large, reniform, conspicuous. The texture of the 

 upper surface of a dried specimen under a two-thirds power has a somewhat squamate 

 appearance. Colour a greyish-brown, diversified with dots and irregular markings of 

 black ; hands long and slender ; dactylos equal in length to the manus. 



"Length, 0-21 inch; width, OIG inch." 



Two specimens from San Diego, California. 



1. Serolis paradoxa (Fabricius) (PL V. figs. 12-14). 



Oniscus paradoxus, Fabricius, Mantissa Insectorum, Hafnise, 1787, t. i. p. 240 ; Systema Ento- 



mologiae, Flensburgi et Lipsise, 1775, p. 296. 

 Cymofhna paradoxa, Fabricius, Entoiiiologia Systematica, Hafniae, 1792^98, Suppl., p. 304, 



and t. ii. p. 503. 

 Serolis fabricii, Leach, Diet. d. Sci. Nat., 1818, t. xii. p. 340. 



Serolis orhigmji, Audouin and Milne-Edwards, Arch. d. Mus. d' Hist. Nat., 1841, t. ii. p. 25. 

 Serolis orhigrmma, Milne-Edwards, Hist. Nat. d. Crust., vol. iiL p. 232. 

 Serolis paradoxa, Miers, Crustacea collected during Survey of H.M.S. "Alert," Proc. Zool. Soc. 



Lend., 1881, p. 61. 



Serolis paradoxa is the type species upon which the genus Serolis was founded by 

 Leach. The animal was first obtained on the shores of Patagonia by Sir Joseph Banks at 

 the close of the last century, and these specimens were described by Fabricius as Oniscus 

 jxiradoxus ; in a subsequent work Fabricius altered the name to Cymothoa paradoxa. 

 In the twelfth volume of the Dictionnaire des Sciences Naturelles, Leach gave some account 

 of this species which he termed " Serolis fabricii." The first full description of the species 

 is contained in the memoir of Audouin and Milne-Edwards,' and subsequently Grube^ 

 in his important Monograph gave a fuller account of this same species, but under the 

 name of Serolis orhigniana. In a short note published in the Journal of the GodeflProy 

 Museum,* Schmeltz called attention to the identity of Serolis fabricii with another 

 species described by Audouin and Milne-Edwards under the name of Serolis orbignyi. 

 More recently Miers, in his account of the Crustacea collected during the voyage of the 

 " Alert," has also pointed out the identity of these two species. 



' Proc. Calif. Acad. Nat. Sci., vol. vii. p. 36. = Loc. cit., p. 25. 



3 Loc. cit., p. 225. ' Part .\ii. p. 161. 



(zooL. CHALL. EXP. — PART xxxm. — 1884.) Kk 5 



