494 Mr. C. T. Regan — A Revision 



red (orange-ferruginous) ; second segment entirely clear red ; 

 third red, with a hirge, suffused, dusky, dorsal shade ; 

 remaining segments black ; third and following segments 

 ■with apical bands of white tomentum, such bands also at 

 sides of second; hair at apex of abdomen white; fourth 

 ventral with a prominent median apical lobe. 



Hub. Nasik, India {E. Comber). Briti!^h Museum. 



Runs in Bingham's table to N. pilipes, Smith, but the 

 colour of the pubescence and wings is so different that it 

 cannot be the male of that species. There is a striking 

 superficial resemblance to A*". pJienacura, Ckll., also found at 

 Nasik, but the sculpture of the thorax is entirely ditterent, 

 especially that of the metathoracic area. 



LXI. — A Revision of the Poeciliid Fishes of the Genera 

 Rivulus, Pterolebias, fl/^rf Cvnolebias. By C Tate Regan, 

 M.A. 



(Publislied by permission of the Trustees of the British Museum.) 



The three closely related genera here dealt with are the 

 neotropical Fundulinse ■^, In them the snout is short, the 

 margin of the eyes is not free, and the gill-membranes are 

 separate. The mouth is rather wide and transverse, with 

 the prjemaxillaries protractile, but not produced, and the 

 lower jaw prominent and very oblique ; the teeth are sub- 

 conical, in bands, with an outer series of enlarged and 

 spaced teeth, more or less canine-like, a lateral pair in the 

 lower jaw being usually the strongest. The membrane 

 connecting the prsemaxillary with the lower jaw folds when 

 the mouth is closed so as to fit into the right angle formed 

 by the very narrow vertical prseorbital and the horizontal 

 nasal. The pectorals are placed low and the pelvics are not 

 far in advance of the anal. 



I give a list of the specimens in the British Museum 

 collection, including the types of four species now described 

 as new. Two of these, Rivulus strigatus from the Amazon 

 and Cynolebias nigripinnis from the La Plata, have been 



* Except that a few species of the nearctic genus Fundulus occur in 

 Central America. 



I take this opportunity of proposing the new generic name Peta- 

 lurichthys, to replace Petalosomci, Regan, 190S, as Mr. C. 0. Waterhouse 

 has kindly called my attention to the fact that this is preoccupied in 

 Coleoptera (Lewis, Ann. & Mag. Nat. Hist. (7) xii. 1903, p. 418). ' There 

 are two species of this neotropical Poeciliid genus, viz. Petalurichthys 

 mltratiis, Regan, 1908, and P. amazonvm, Regan, 1911. 



