290 BLUEFIELDS. 



charms are not confined to mere richness and variety 

 of colour. In this little Clupea a singular effect is 

 produced by the sides being marked with narrow lon- 

 gitudinal bands, not of colour, but produced by a 

 slight difference in the mode in which the pearly 

 light is reflected. In the " Herring " a species of 

 the same Family, but belonging to a genus {Chat- 

 oessus) marked by the last ray of the dorsal being 

 prolonged into a whip-like filament, the back is steel- 

 blue, the sides and belly silvery, with longitudinal 

 lines liiglilij polished ; the whole fish appearing as if 

 made in metal.* 



The Jacks, too, just named, are remarkable for the 

 brilliant opaline reflections, which their bodies pre- 

 sent, quite distinct from their permanent colours. 

 The reflected hues are principally flushes of purple on 

 the back, and of flame-colour on the sides. These 

 bold and voracious fishes are members of the great 

 Mackarel family : they are distinguished as Buntung 

 Jack, Round-headed, or Ground Jack, and Cavally 



* This seems to be new. Chatoessus eumorphus, mihi. The Elegant 

 Bristle-herring. Form very gracefully spindle-shaped; outlines of 

 back and belly uniformly arched from muzzle to caudal ; belly-line 

 more curved than that of the back. Height barely one-fourth of total 

 length (reckoned to the fork of caudal) : head (from muzzle to gill 

 aperture), to total length, as 1 to 5\. Mouth very small, sub-vertical. 

 Dorsal triangular, pointed, hollowed ; filament reaching to base of 

 caudal : pectorals small, pointed : ventrals minute ; anal very low, of 

 equal height all along : caudal deeply forked, with the lobes acutely 

 pointed. Belly scarcely serrate. Length seven and a half inches. 

 The colour is described in the text. Irides silvery. 



This species differs considerably in form from Ch. cepediamis, the 

 only occidental one mentioned by Cuv. and Val. ; it approaches C. 

 nasus of the Indian Ocean, but is distinguished from it by the longi- 

 tudinal lines, and also by its proportions. 



