270 On a new CicJilid FisJi from the La Plata. 



two perfectly distinct species, one western (anceps, Bougain- 

 ville) and one eastern [atrata, Guadalcanar). The faunistic 

 areas o£ the Solomon Arciiipelago indicated by the distribu- 

 tion of the five species of the Pteropus rayneri group are 

 very nearly the same as those recognized by ornithologists (see 

 W. Rothschild and E. Hartert, Nov. Zool. xii. pp. 243-244, 

 1905). 



XXXIII. — Description of a neio Ckhlid Fish of the Genus 

 Heterogramma/rom the La Plata. By C. Tate Kegan, M.A. 



Lleterogramma pleuroi<^7iia. 



Depth of body 2? in the length, length of head 2|. Snout 

 shorter than eye, the diameter of which is 3 in the length of 

 head ; interorbital width 3| in the length of head. Depth of 

 prseorbital ^ the diameter of eye. Maxillary extending a 

 little beyond the vertical from anterior edge of eye; jaws 

 equal anteriorly ; fold of the lower lip continuous ; cheek 

 with 4 series of scales ; no distinct gill-rakers on the lower 

 part of the anterior arch. Scales 23 j ; upper lateral line 

 well developed on 8 or 9 scales only ; lower lateral line 

 vestigial or absent. Dorsal XVI 6; spines subequal from 

 the fourth, the last § the length of head. Anal IV 5. Pec- 

 toral nearly as long as the head. Caudal rounded. Caudal 

 peduncle deeper than long. A dark lateral stripe from eye 

 to base of caudal ; a broad oblique blackish bar from eye to 

 interoperculum ; caudal fin with a few transverse bars or 

 series of spots ; outer edge of pelvic fin dusky. 



A single specimen, 40 mm. in total length, from the La 

 Plata, received from Herr J. Paul Arnold. 



The diflferent coloration, somewhat deeper body, lower 

 spines, narrower interorbital region, &c. distinguish this 

 species from the allied JL. corumhce and H. trifasciatum. A 

 specimen of //. corumhce in the British Museum has IV 5 

 anal rays, and it is probable that in the species here described 

 the normal number is III 6-7. 



