THE SQUIRREL-FISHES 



Family A'A'A'. Holoccntrid& 



BODY oblong or ovate, moderately compressed, covered with 

 very strong ctenoid or spinous scales; head with large muciferous 

 cavities; eyes lateral, very large; preorbital very narrow; mouth 

 moderate, oblique; premaxillaries protractile; maxillary very large, 

 with supplemental bone; bands of villiform teeth on jaws, vomer 

 and palatines; opercular and membrane bones of head generally 

 serrated or spinescent along their edges; branchiostegals 8; gill- 

 membranes separate, free from the isthmus; pseudobranchiae present; 

 no barbels; sides of head scaly; lateral line present; dorsal fin very 

 long, deeply divided, with about 1 1 strong spines depressible in 

 a scaly groove; anal with 4 spines, the third longest and strongest; 

 ventrals thoracic, with one spine and 7 rays; caudal deeply 

 forked, with sharp rudimentary rays or fulcra at base; vertebrae 

 about 27; pyloric coeca 8 to 25; air-bladder large, sometimes con- 

 nected with the organ of hearing. General colour red. Genera 

 4, species about 70, gaily-coloured inhabitants of tropical seas, 

 abounding about coral reefs. Only 4 genera and about 12 species 

 in our waters. 



a. Preopercle without conspicuous spine at its angle. 



b. Scales very large and rough, about 30; . . Ostichthys, 264 



bb. Scales moderate, 35 to 45 ; Mynprislis, 265 



aa. Preopercle with a conspicuous spine. 



c. Suborbital arch simply serrated, scales moderate. 



d. Mouth moderate; lower jaw slightly included, its length less 



than half head ; '.' Holoccntnts, 265 



ilJ. Mouth very large; lower jaw projecting, its length more 



than half head ; Hlammeo, 266 



<v. Suborbital arch armed with three long spines curved for- 

 ward Wcctrypops, 267 



The genus O.s7/<7////rs is known by its very large scales. The 

 single species, O. irji-liyponius, is found only in the West Indies, 

 particularly about Cuba, and even there it appears to be rare. 

 Colour, carmine red, darker above; side with about 10 alternate 

 streaks of deep red and rose; fins all red. 



264 



