330 MR. F. E. BKDDARD ON THE ISOPODA COLLECTED [May 20, 



1. Preliminary Notice of the Isopoda collected during the 

 Voyage of H.M.S. ' Challenger '.—Part I. Serolis. By 

 Frank E. Beddard, M.A., F.R.S.E., F.Z.S., Prosector 

 to the Society 1 . 



[Keceived May 20, 1884.] 



The specimens of Serolis dredged during the voyage of the 

 ' Challenger ' are referable to sixteen species, of which seven have 

 been more or less fully described by previous writers. Six of these 

 species are as follows : — Serolis cornuta, Studer ; Serolis latifrons, 

 White; Serolis septemcarinata, Miers (= Serolis ovalis, Studer); 

 Serolis paradoxa, Fabr. sp. ( = Serolis Orbigniana, M.-E.); Serolis 

 schythei, Ltk. ; Serolis tuberculata, Grube. There is besides a single 

 specimen which is closely similar to the type specimens of Serolis 

 convexa, Cunningham, preserved in the British Museum, but shows 

 certain slight differences in which it more closely resembles Serolis 

 plana, Dana ; I am inclined to think that these two species are 

 identical. The chief character which Grube uses to differentiate 

 Serolis convexa from Serolis plana, and also Serolis gaudichaudii, 

 is the presence in the former of a tuft of hairs upon the fourth joint 

 of the second thoracic appendages. Having examined both Serolis 

 convexa and Serolis gaudichaudii, I am able to state that it is the 

 males only and of both these species which are thus characterized 2 . 

 Serolis gaudichaudii is, however, quite a distinct species, and cannot 

 be confounded with Serolis convexa. Besides these seven species six 

 other species of the genus Serolis are known, viz. : — S. serrei, Lucas ; 

 S. gaudichaudii, M.-E. ; S. carinata, Lockington; S. plana, Dana; 

 S. trilolitoides, Eights; and S. acutangula, Grube. Of these Serolis 

 acutangula is probably identical with some other form, since Grube, 

 who originally described it, omits all mention of it in his subsequently 

 published monograph of the genus ; Serolis plana appears to me to 

 present no clearly defined differences by which it can be with certainty 

 separated from Serolis convexa ; the figure given by Eights of Serolis 

 trilolitoides is so poor, and his description, which does not in all 

 respects tally with the figure, so incomplete that it is not easy to 

 distinguish this species from Serolis cornuta, St. Further details 

 are required concerning Serolis serrei and Serolis carinata. 



The total number of species of Serolis at present known with 

 certainty is therefore eight. 



The nine new species in the ' Challenger ' collection I propose to 

 name as follows : — 



Serolis bromleyana (Suhm). 

 Serolis necera. 

 Se)-olis gracilis. 

 Serolis antarctica. 

 Serolis australiensis. 



Serolis elongata. 

 Serolis pallida. 

 Serolis longicaudata. 

 Serolis minuta. 



1 Published by permission of the Lords Commissioners of the Treasury. 



2 Since the above was written I find that Studer (Abhandl. d. Kim. Preuss. 

 Akad. Wiss. Berliu, 1883) has come to a similar conclusion. 



