372 Records of the Indian Museum. [Vol. XII, 



Pontophilus hendersoni, Kemp, 



1915. Pontophilus hendersoni. Kemp, Mem. Ind. Mns., V. p. 261, pi. xiii, 

 fig. 8. 



The characters given in the key on pp. 356 and 357 will suffice 

 to distinguish this species from all other Indian representatives of 

 the genus. 



P. hendersoni is very closely allied to P. megalocheir (Stebbing) ', 

 obtained at depths of 25 and 37 fathoms on the coast of S. Africa. 

 The African form agrees in nearly all respects with that from the 

 Indian coast; in particular, there is (as shown in Stebbing's figures) 

 an almost complete identity of form in the structure of the subchela, 

 the 'thumb ' being composed of two closely juxtaposed spines in- 

 stead of the single one found in all other species of the genus. 



There are, however, certain discrepancies between Stebbing's 

 account and my own, which, if substantiated, are sufficient to 

 justify the separation of the two forms. The apex of the lamella 

 of the antennal scale is, for instance, much more acute in P. megalo- 

 cheir than in P. hendersoni , extending much further beyond the 

 apex of the spine that terminates the outer margin (c/. Stebbing's 

 pi. Ixxix, fig. a.i. and my text-fig, 25a). Stebbing also has made 

 no mention of the small tubercle found in P. hendersoni on the dor- 

 sum of the third abdominal somite and the armature of the telson 

 is totally different. In P. megalocheir the telson is furnished at 

 its apex with a long and slender tooth, flanked by a pair of plu- 

 mose setae {v. Stebbing, pi. Ixxix, fig. T). In P. hendersoni the 

 apex consists of a triangular plate with a minute spinule on either 

 side and with two pairs of plumose setae arising from beneath it 

 {v. Kemp, text-figs. 25 g, g'). 



Since the original account of P. hendersoni was published, 

 additional specimens have been taken in the open sea on the Orissa 

 Coast, a circumstance which tends to confirm the view that the 

 occurrence of the species in the outer channel of the Chilka Lake 

 was purely accidental and that it is not normally an inhabitant of 

 brackish water. 



8|Sfi Puri, Orissa coast, 4-4! fms. S. Kemp. 3, 6^-9 mm. 



Pontophilus parvirostris, sp nov. 

 (Plate viii, fig. 6.) 



The rostrum is extremely small, far less conspicuous than in 

 any other species of the genus. It recalls that found in many 

 Pagurids and consists merel}' of a small flat triangular prolonga- 

 tion of the median part of the carapace. The apex is acute and 

 does not reach further than to one third the length of the eyestalks. 



The antennal spine is sharp and extends far be^^ond the level 

 of the rostral apex ; the branchiostegal spine is long and reaches 



1 Philocheras megalocheir, Stebbing, Ann. S. African Mus., XV, p. 71, pi. 

 Ixxix (1015). This work was not received in Calcutta in sufficient time to enable 

 me to refer to it in my account of the Decapods of the Chilka l.aki-. 



