120 FISH HARVESTING. 
Mediterranean, and occasionally on the French 
and Spanish coasts. But a close investigation 
into the more marked generic and specific charac- 
ters, apart from their reproducing organs, at 
once clearly shows they belong neither to the 
one family nor the other;. they differ much more 
from the percoids than from the sparoids, but 
the cycloid scales remove them at once from the 
sparoids, in which the scales present a very 
uniform ctenoid type. 
The illustration represents a female Ditrema 
argenteum, Brit. Mus. Cat., ‘ Fishes.’ 
Amphistichus argenteus, Agass., Am. Journ., 
1354) S0c./ Nat. Hist., 1861, p.. 151% Bae 
R. kh. Exp., ‘ Fishes,’ p. 201. 
Mytilophagus fasciatus (Gibbons). 
Amphistichus similes (Grd.). 
The middle dorsal spines are either nearly as 
long as, or somewhat longer, than the posterior ; 
scales on the cheek, in five series, somewhat 
irregularly disposed. The height of the body 
is rather more than a fourth of the total length 
(without caudal); jaws equal anteriorly; the 
maxillary extends to below the centre of the 
orbit; lips thin, the fold of the lower interrupted 
in the middle. For description of species, vide 
Appendix, vol. ii. 
