XXIII ACANTHOPTERYGII ZOU 
finger-like appendages of the pectoral fins, which are employed 
to feel the ground in search of crustaceans and other small 
animals on which they feed; also for the grunting sounds which 
they utter by the contraction of the air-bladder. About 50 
species are known, referable to 4 genera: Prionotus, Trigla, 
Lepidotrigla, Peristedion. Fossil remains referred to TZvrigla 
have been found in Miocene and later formations. sritish 
species are the Grey Gurnard (7rigla gurnardus), the Red 
Gurnard (7’. cuculus), the Tub or Sapphirine Gurnard (7. hirundo), 
the Piper (7. lyra), the Long-finned Gurnard (7. obscura), and 
the Streaked Gurnard (7. lineata). 
Fam. 11. Dactylopteridae.— Head completely cuirassed ; 
_basis cranii simple ; parietal bones meeting on the median line ; 
two nostrils on each side. Gill-cleft broadly separated by scaly 
isthmus; gills 4; pseudobranchiae present. Vertebrae 20-22 
(8-9 + 12-13), the first very elongate and formed by the fusion 
Fic. 426.—Dactylopterus volitans. (After Gill.) 4 nat. size. 
of three or four; ribs sessile, no transverse processes. Post- 
temporal fused with the skull; no supraclavicle; scapula and 
coracoid well developed, in contact with each other; pectoral 
rays divided into two parts, inserted on the scapula and on 4 
elongate pterygials, of which 3 are in contact with the coracoid. 
Ventral fins close together, with 1 spine and 4 soft rays. 
Spinous dorsal shorter than the soft; anal without spines. Body 
covered with hard, rough scales. 
The “Flying Gurnards,” of which four species are known, 
belonging to a single genus (Dactylopterus), are inhabitants of the 
tropical and warm parts of the Atlantic and the Indian Ocean 
and Archipelago. They are remarkable, when adult, for the 
