344 Rev. T. R. R. Stebbing on Amphipodous Crustaceans. 



comparatively long- antenna?) being the male. It may be open 

 to question whether Lysianassa atlantica may not be the young 

 of Lysianassa longicornis ; but any one who will read atten- 

 tively tne accounts given by Messrs. Bate and Westwood of 

 Urothoe marimis^ U. hrevicornis, and U. elegans in the light 

 of what has been said of the species oi Anonyx and (in a former 

 paper) of the species of Bathyjioreia^ will scarcely escape the 

 conviction that these three descriptions belong to one species. 

 The variation of colour exhibited by Urothoe elegans is not 

 uncommon, as in Ipliimedia ohesa, Calliope la'vtuscula, and, 

 to a striking extent, in Cyrtophium Darwini *. 



It should be added that the white integument of the various 

 specimens of Anonyx discussed in this paper displayed similar 

 markings — markings very indehnite in shape, but many of 

 them angular and looking like short disconnected scratches. 

 The abrupt junction of the long narrow flagellum to the broad 

 end of the peduncle in the lower antennaj of the full-grown 

 male is also worthy of notice. In tlie other specimens, the 

 peduncle being itself comparatively narrow, there was no special 

 abruptness in its junction with the flagellum. 



ProhoUum Spence-Batei^ n. sp. 



This pretty little species was taken in December of last 

 year from a tidal pool at Goodrington, in Torbay. The soli- 

 tary specimen obtained was a female with eggs. It measured 

 about one tenth of an inch in length. It has all the characters 

 of the genus ProhoUum of Costa, which answers to the genus 

 Montagua of Spence Bate. The specific name is given in 

 honour of this latter author, who has done so much to make 

 known the curious varieties and varied beauty of Sessile-eyed, 



* An extract from the ' Comptes Rendus ' for Jan. 3, 1876, p. 76, in 

 the last number of the 'Annals ' (March 1876), shows me that the sexual 

 character of the long antennae in Urothoe has been already observed by 

 M. A. Giard. In an interesting notice of the commensalism of this crus- 

 tacean with a sea-urchin, M. Giard di-aws the inference, in regard to the 

 species named in the ' British Sessile-eyed Crustacea,' that one sex only 

 has been described for each of the known types, that Urothoe Bairdi and 

 Urot 'toe elegans must be regarded as representing male individuals, whilst 

 Uro hoe brevicornis and Urothoe marinus are, on the contrary, figured from 

 the female sex. 



From the plumosity of the terminal caudal appendages, I had myself 

 been inclined to class Urothoe marinus as a young male. But possibly 

 this plumosity may depend on the time of life, and not on the sex. The 

 relative sizes of the specimens, as given in the text of tlie British-Museum 

 Catalogue, would then suggest that U. tnarinus is an adult female, ZL bre- 

 vicornis the undifferentiated young. In a solitary specimen obtained from 

 Goodrington sands, Torbay, the eyes approach the reuiforai shape assigned 

 to those of U. eler/ans, while the antennae agree with those of U. marinus. 



