418 
SPINY-FINNED GROUP. 
The Wrasse-Like Fishes, —Families P omagentridie, L abridge, 
Chromidibje, etc. 
In almost all the families of spiny-finned fishes hitherto described the lower 
pharyngeal hones are completely separated from one another, whereas in the 
four families remaining for consideration these are united with one another. It 
has been considered that this difference was of sufficient importance to justify 
the reference of the families with united pharyngeals to a subordinal group of 
equal rank with one containing those in which these bones remain distinct; but we 
prefer to follow Day in regarding the group now to be considered merely as a section 
of the suborder which includes all the other spiny-finned fishes. That this is the 
correct view is proved by the circumstance that in one aberrant genus of perches 
SILVER-DOTTED POMACENTRUS (§ liat. size). 
( Gerres ) some of the species have the lower pharyngeal bones separate, while in 
others they are united. In the three families constituting the present group 
there is a single dorsal fin, in which the number of spines and soft rays is 
nearly equal; while the anal is usually similar in character to the soft dorsal; 
and the pelvic fins are thoracic in position, and include one spine and five 
soft rays. 
Pomacentrus ^he ^ ie ^ am ili es °f the present sectional group takes its 
name from the genus Pomacentrus, which, together with the allied 
genera, includes tropical fishes mainly frequenting the neighbourhood of coral- 
reefs and islands, and thus closely resembling the scaly-finned fishes (p. 343) 
in their mode of life; a few species of the family range, however, into the seas 
of the temperate zones. As an example of the typical genus, we figure P. scolopsis, 
from the Malayan seas and Polynesia. As a family, these fishes are specially 
characterised by the presence of false gills and ctenoid scales. In form, the body 
