120 Mr. A. Patience on the 



Dexamine dolicJwnyx, Nebeski, in having the peculiar iucision 

 in the upper or front margin of the hand of one of the 

 gnathopods, but according to our experience the peculiarity- 

 belongs to the first gnathopods_, not to the second to which 

 Nebeski ascribes it.'^ 



Neither Sclincider (5) nor Scott (10) makes any reference 

 to the sexual character of the male here referred to, although 

 the former has lully described and figured the species. 



In endeavouring to clear up this matter I sent males of 

 D. thea to Professor G. O. Sars, Rev. T. R. R. Stebbing, 

 and Canon Norman, and enquired whether they were aware 

 of the peculiarity of the incised gnathopod iu that sex, but 

 it had not been observed by any of them. Professor Sars, 

 however, having examined his specimens, kindly sent me 

 the two sexes from Norway, and Canon Norman wrote that 

 on examination he now found the characteristic male in his 

 collection from several British localities, including the two 

 extremes Shetland and Jersey, and also among his last 

 Finmarkian gatherings ; and that the male was evidently 

 the true Dexamine dolichonyx, as was evident by Nebeski^s 

 description of the spines on the metasome and his figure of 

 the extremity of the second perseopod ; and therefore those 

 English authors who have regarded Nebeski^s species as the 

 male of Tritceta yibbosa have been in error. Subsequently 

 to this he has informed me that in answer to his request 

 M. Chevreux had sent him specimens of what he had called 

 J>. dolichonyx, and that these also were the males of Tritceta 

 i/ilbosa. A reading of Chevreux's text (7), however, in 

 which he says " L^'espece est bien netteraent caracterisee 

 2)ar les dente/urcs (pii bordeut les e/Anieres des qiudre premieres 

 jjuires" leads one to the belief that he had then under 

 examination D. thea, the characters of which he had rightly 

 appreciated. Thus all references to Nebeski up to the 

 present time, with probably the doubtful exception of 

 Chevreux''s, have been erroneous. 



The two genera here under consideration comprise three 

 Briti>ih species : Tritata gibbosa (Bate), Dexamine thea, 

 Boeck, and D. spinosa (Mont.). The following short 

 synoptic table may be useful for the discrimination of these 

 genera and species : — • 



iPerfeopods l-o, 4tli joint longer tliau 6tli 

 and 6t]i combined I. Tnttbta ijihhosa. 

 Peraeopods l-o, 4tli joint shorter than oth 

 and 6th combined." — 2, 



iy \ Perfeopod 6, 2nd joint sublinear 2. Dexamine thea. 



' \ Peiseopod 0, 2ud ioint lamiuar .,..,...,, 3, D. sjnnosa. 



