66 U.S. NATIONAL MUSEUM BULLETIN 202 Vol. 2 



pale, whereas that area is dark brown or blackish in specimens from 

 the East Indies to the Red Sea and Mam-itius. We believe the speci- 

 mens from the central tropical Pacific may represent a distinct sub- 

 species. D. albisella from Honolulu, plate 82,D, is a distinct species. 

 The detailed relationships of this gi'oup of species and subspecies re- 

 main to be worked out. 



Genus CHROMIS Cuvier 



Chromis Cuvier, Mem. Mus. Hist. Nat. Paris, vol. 1, p. 393, 1815 (type species, 

 Sparus chromis Linnaeus). 



KEY TO SPECIES OF CHROMIS FROM THE NORTHERN MARSHALL ISLANDS 



la. Preopercle finely serrate; scales of nape and back with small basal auxiliary 

 scales; lower margin of suborbital partly free; upper parts dark brownish; 

 sides and belly lighter; pelvics dusky, anterior portions soft dorsal and 

 anal dark, posterior rays pale; outer caudal rays dusky, median rays 

 pale; dorsal rays XII, 11 or 12; anal 11,11; pectoral ii,16. 



C. lepidolepis Bleeker 



16. Preopercle entire or urenulate; no basal auxiliary scales on nape or back. 



2a. Soft dorsal and anal bases naked, outer row of teeth of lower jaw directed 



outward near symphysis; margin of suborbital obscure, hidden by 



scales; soft dorsal and anal membranes hyaline; outer caudal rays 



dusky; pelvics pale or slightly dusky; dorsal rays XII, 10 (sometimes 



9); anal 11,10 (rarely 11,9). 



3a. Pectoral rays usually ii,15 or 16 (occasionally 17); pectoral axil dusky but 



not completely black C. caeruleus (Cuvier and Valenciennes) 



36. Pectoral rays usually ii,17 or 18 (occasionally 16 or 19); pectoral axil 



black C. atripectoralis Welander and Schultz 



26. Soft dorsal and anal bases scaled; outer row of teeth of lower jaw not 



directed outward. 



4a. Pectoral base with a large black spot, pectoral axil black; suborbital 



margin free, distinct; caudal peduncle and caudal fin pale yellowish; 



pelvics black. 



5a. Head and body dark purplish brown; caudal peduncle abruptly pale, 



soft dorsal dark brown on bases of first 2 or 3 rays, the rest entirely 



pale or white; dorsal rays XII,12; anal 11,12; pectorals ii,15; 



tubular scales in upper part of lateral line 17 or 18; gill rakers 



8+1 + 19 = 28 C. dimidiatus (Klunzinger) 



56. Head light yellowish brown, back, sides, and caudal peduncle, light 

 purplish brown; soft dorsal with first four rays entirely brown, the 

 rest dark basally, pale distally; dorsal rays XII,13; anal 11,12 to 

 14 (usually 13); pectorals ii,14 or 15 (usually 15); tubular scales 

 in upper part of lateral line 15 or 16 (usually 15); gill rakers 8 or 



9+1 + 21 or 22 = 31 or 32 C. leucurus Gilbert 



46. Pectoral base without large black spot; pectoral axil pale; suborbital 

 adnate, its margin not evident; broad distinct brown lengthwise 

 band on upper and lower caudal rays; pelvics pale; dorsal rays 

 XII.ll; anal 11,11; pectorals ii, 15 or 16 C. tematensis (Bleeker) 



