358 A HISTORY OF EECENT CRUSTACEA 



this was removed from the fossil genus and twice renamed 

 as Serolis Brongniartiana and as Serolis trilobitoides. Bed- 

 dard considers it to be perhaps the same as Studer's Serolis 

 comuta from the Crozets and Kerguelen. The distribution 

 of the genus is rather peculiar, for though the type, first 

 reported from Tierra del Fuego, is said by Leach to occur 

 also on the coast of Senegal, and Serolis carinata, Locking- 

 ton, has been recently described from California, all the 

 other species belong to the Southern hemisphere. The 

 shallow- water species do not even extend north of latitude 

 30° S., and though some of the deep-water species approach 

 the equator, none of them pass to the north of it. Serolis 

 necera, Beddard, was dredged up from a depth of 2,040 

 fathoms, and Serolis Bromleyana, v. Willemoes Suhm, 

 from the slightly smaller depth of 1,975 fathoms. The 

 latter somewhat exceeds the former species in size, and is 

 the largest in the genus. The male is more than two 

 inches long and more than two inches broad, and, if the 

 length is reckoned not along the central line but from the 

 rostrum to the end of the greatly produced sixth side- 

 plate, it exceeds three inches. All the deep-sea species 

 except Serolis anta/retica, Beddard, agree in having these 

 side-plates greatly produced, especially in the male. The 

 Australian Serolis minuta, Beddard, only a sixth of an inch 

 in length and in breadth, is the smallest species known. 

 Five other species belonging to Australia form a con- 

 nected group, in which the dorsal portion of the sixth 

 pereeon-segment is extremely narrow, and that of the 

 seventh is either absent or fused with the first of the pleon. 

 In these characters they agree only with Serolis minuta, 

 and are separated from that by having the side-plates of 

 the pleon undeveloped. These Australian species are 

 named australiensis, elongata, pallida, longicaudata, by Bed- 

 dard, accompanying the earlier tubercidata of Grube. The 

 island of Kerguelen, so richly supplied with sessile-eyed 

 Crustacea, has three species, Serolis comuta, Studer, Serolis 

 septemcarinata, Miers, and Serolis latifrons, White. 



Mr. Beddard finds that the deep-sea species are distin- 

 guished in an important manner from those of shallow 



