FISHES OF THE PHrLIPPINE AND ADJACENT SEAS 3 



Family POMACENTRIDAE 



Body short, deeply ovoid, and well compressed. Snout short, often 

 obtuse. Eye moderate, or large. Mouth small, terminal. Teeth 

 only in jaws, conic or compressed incisors, palate edentulous. 

 Preorbital sheaths maxillary. Single nostril each side of snout. 

 Hind preopercle edge free, entire or serrated. Gill membranes free 

 from the isthmus. Gills 3I/2. Pseudobranchiae present. Branchi- 

 ostegals 5 to 7. Low^er pharyngeals entirely joined as a single bone. 

 Subocular shelf and entopterygoid present. Fourth to fifth vertebrae 

 with transverse processes; ribs, when present, attached to transverse 

 processes of vertebrae. Scales usually minutely ctenoid, variable. 

 Soft dorsal, anal and caudal scaled basally. Ventral axil with scaly 

 flap. Lateral line divided, as upper anterior arch of tubes and 

 lower posterior median section of simple pores, of which few or 

 none on caudal base. Dorsal fin long, single, with many strong 

 spines, and spinous fin longer than soft fin. Soft dorsal and anal 

 similar. Anal spines 2. Paired fins usually long, ventral with spine 

 and 5 rays, of which front ray longest and usually filamentous. 



Small, shapely fishes, compact in form, and most very brilliant 

 or strikingly colored. They abound in the reefs of tropical seas, 

 especially about coral heads, frequently in tide or rock pools. Many 

 are extremely active and wary, so that only occasional specimens are 

 obtained in small hauling seines. The extensive series obtained in the 

 Philippines were most all secured by means of dynamite. They are 

 frequent with many and greatly diverse invertebrate associations. 

 Many feed on small marine animals, though those with incisor teeth 

 are adapted to a herbivorous life. 



ANALYSIS OF THE GENERA 



a\ Teeth conic or villiform, not compressed. 



b\ PREM^fiNAE. Preorbital witti strong spine extended backward. 



Premnas. 

 &^ Chbominae, Preorbital without strong spine. 



e^. Some of opercles with serrae Amphiprion. 



d\ All of opercles serrate. 



d'. Preopercle alone, sometimes preorbital, serrated, 

 e". Dorsal spines 12 or 13. 



f. Less than 30 scales in median lateral series Dascyllus. 



f. More than 30 scales in median lateral series lepidozygus. 



e". Dorsal spines 17 Acanthochromis. 



c^. None of opercles serrated ; lateral line not developed on tail Chromis. 



o*. PoMACENTRiNAE. Teeth more or less compressed. 



fif'. Lips greatly thickened, fimbriate and curled back over 



snout Cheiloprion. 



g^. Lips normal. 



