No. VIII.— ON THE PONTONIIN^. 



By L, a. Borradaile, M.A. 



{Lecturer in Zoology in the University of Cambridge, Fellow, Dean, and Lecturer 



of Selivyn College.) 



(Communicated by Prof. J. Stanley Gardiner, M.A., F.E.S., F.L.S.) 



(Plates 52—57.) 



Read 2nd November, 1916. 



FOREWORD. 



The collections made during Professor Stanley Gardiner's two expeditions to the 

 Western Indian Ocean are particularly rich in Pontoniinee, and contain many new 

 species, some of which are of peculiar interest. In view of these facts, and of the 

 large additions to our knowledge of the group that have been made since my revision 

 of it in 1898, I have thought well again to revise it as a whole*. The results of my 

 labours are embodied in the present paper. 



The following is a list of the species collected, with a statement of the localities 

 in which they were taken : 



1. Urocaridella gracilis Borradaile, 1915. Suvadiva, Kolumadulu, and Haddu- 

 mati Atolls. 



2. Urocaris sp., ? U. longicaudata Stimpson, 1860. N. Maid Atoll, Amirante. 



3. Urocaris psamathe de Man, 1902. N. Male Atoll, Diego Garcia. 



4. PalcBmonella tridentata Borradaile, 1899. Goidu, Goifurfchendu Atoll, S. 

 Nilandu Atoll, Salomon, Coin, Peros Banhos. 



5. Palcemonella elegans Borradaile, 1915. Salomon Is. 



6. PalcBmonella longirostris Borradaile, 1915. Reef, Naifaro, FadifFolu Atoll. 



* The present article was finished towards the end of the year 1914. Since then there have been 

 described the following new species which probably or certainly belong to the Pontoniinse. 



(1) Paratypton siebenrocki Baiss, 1915 (Zool. Anz. xlv. p. 83), lied Sea and Samoa. A remarkable 

 coral commensal, superficially resembles Conchodytes. As neither the telson nor the gill formula are 

 described it is not certain that this is a member of the Pontoniinse. 



(2) Urocaris indica Kemp, 1915 (Mem. Tnd. Mus. v. p. 279), Chilka Lake, India. Perhaps accounts 

 for Pearson's report of U. longicaudata from Ceylon. Lives in water whose salinity varies, and which is at 

 times nearly fresh. 



(3) Periclimenes demani Kemp, 1915 (loc. cit. p. 275). A member of the subgenus Falciger. From 

 the same waters as U. indica. 



(4) Periclimenes (Bamiger) novce-zealandice Borradaile, 1916 (Brit. Antarct. ("Terra Nova") Exp. Rep., 

 Zool., in, 2, p. 87, 1916), New Zealand. Representative of a new subgenus and possibly of a new genus. 

 First chela has fingers fringed with long curled hairs, second pair unequal, one very large and of abnormal 

 shape. Hepatic spine absent. Ischiomeropodite of third maxilliped somewhat broadened. 



41—2 



