452 Records of the Indian Museum. [Vol,. VIII, 



stage they resemble more or less closely, those of the female. I, 

 therefore, regard the present specimens as males which have not 

 yet undergone complete metamorphosis. It will be seen from the 

 figures that the first gnathopods of these immature specimens 

 differ from those of the females in being subchelate instead of 

 simple, but they have not yet attained the full subchelate form of 

 the adult male, in that the nail more than covers the palm whereas 

 in adult males, the nail is shorter than the palm. The shagreened 

 lobes on the merus, carpus and propodus, moreover, are not so 

 completely developed. The second gnathopods, on the other hand, 

 resemble those of female specimens almost completely. The 

 interest of these specimens lies in the fact that their gnathopods 

 have the form characteristic of females of the genus Orchestia. 

 In other words, if my interpretation of their nature is the correct 

 one, we have here a species of Talorchestia in which the male passes 

 through a female Orchestia stage during metamorpho.sis. I do 

 not think it is a question of two species living together. All the 

 specimens were collected together, in the same place, at the same 

 tim^e and agree closely in all details except in the form of the 

 gnathopods. It does seem to me to indicate how very slender 

 are the grounds on which certain genera of Talitridae have been 

 instituted, and how very important it is to have a complete range 

 of specimens before attempting to increase the number of genera. 

 If only the immature and mature males of T. keinpii had been col- 

 lected, the species would have been referred to the genus Orchestia. 

 On the other hand, if onh' females and mature males had been 

 found, the species would, with equal justice, have been referred to 

 Talorchestia. May not the validity of these two genera be justly 

 questioned in the light of the present material and may not one 

 go lurther and inquire how many species of either genera have 

 been instituted on specimens of the nature of those I have inter- 

 preted as immature males ? 



For the rest, T. kenipii is very closely related to T. parvis- 

 pinosa and only differs in the rather different form of the pro- 

 podus of the second gnathopod of the male and in the armature 

 of the telson. We are indebted to Chilton (191 2) for a description 

 of the telson of T. parvispinosa and his figure depicts three long 

 spines on each margin in addition to the apical spines. In T. 

 kenipii there is but one spine on each lateral margin, and this 

 character is constant in all the specimens in the collection. It 

 may be useful to indicate the position of these two species in 

 Stebbing's key to the genus. They come at the end of the 

 table which ma}' therefore be extended as follows: — 



Gnathopod 2 in the male, palm excavate 

 r,\ near finger-hinge .. 18. T. iwvaeholIa)idiae, 



\ Gnathopod 2 in the male, palm not ex- 

 cavate near finger-hinge .,, 19. 

 ' Gnathopod i in the male, nail longer than 



\ the apex of the 6th joint . ig. T. niartensii. 



^ \ Gnathopod i in the male, nail shorter 



than the apex of the 6th joint ... 20. 



