BULLETIN OF THE UNITED STATES FISH COMMISSION. 
47 2 
continuous or divided. Pectoral fin short, with the 2 lowermost rays detached. Ventrals i, 5, sepa¬ 
rated by a broad, flat area. Air-bladder simple. Pyloric ceeca about 10. Color generally red. Deep- 
sea fishes; 2 or 3 genera and about 13 species known, bearing some resemblance to young sturgeons. 
Genus 219. PERISTEDION Lacepede. 
Barbels large, forming large fringed tufts at angles of mouth and on lower jaw; dorsal fins 2; 
characters otherwise included above. 
The 2 Hawaiian species of this genus are fully described in Section II. 
Peristedion Lacdpfede, Hist. Nat. Poiss., Ill, 308, 1801 ( malarmat ratnphmitum ). 
Peristethus Kaup, Proo. Zool. Hoc. Land. 1859, 103 (cataphractus): amended spelling. 
Family LXXXV111. HOPUCHTHYIffeE. 
Head broad, very depressed, with the snout produced and rounded anteriorly, strongly armed, 
and with the upper surface and sides bony; back and sides of the body covered with bony plates; 2 
dorsals, the first, much shorter than the second; no pectoral filaments; ventrals inserted a little before 
the pectorals; minute teeth in the jaws, on the vomer and the palatine bones; air-bladder none; 
pseudobranchise present. 
Genus 220. HOPLICHTHYS Cuvier & Valenciennes. 
Characters of the genus included above. 
The 2 Hawaiian species of this genus are fully described in Section II. 
Hoplirhthns Cuvier A: Valeilcicnucs, Hist. Nut. Poiss., iY, L'titi, 1H'J9 {lani/sdorfii). 
Family LXXX1X. CEPHALACAXTHID.-E. —The Flying Gurnards. 
Body elongate, subquadrangular, tapering behind ; head very blunt, quadrangular, its surface almost 
entirely bony; nasals, preorpitals, suborbitals, and 1 tones of top of head united into a shield; nuchal part 
of shield on each side produced backward in a bony ridge, ending in a strong spine, which reaches 
past front of dorsal; interocular space deeply concave; preorbitals forming a projecting roof above the 
jaws; preopercle produced in a very long, rough spine; cheeks and opercles with small scales; opercle 
smaller than eye; gill-openings narrow, vertical, separated by a very broad, scaly isthmus; pseudo¬ 
branchise large; gillrakers minute; mouth small, lower jaw included; jaws with granular teeth; no teeth 
on vomer or palatines; scales bony, strongly keeled; 2 serrated knife-like appendages at base of tail; 
first dorsal of 4 or 5 rather high flexible spines, the first 1 or 2 spines nearly free from the others; an 
immovable spine between the dorsals; anal and second dorsal Short, of slender rays; caudal small, 
lunate; pectoral tins divided to the base into 2 parts, the anterior portion about as long as the head, of 
about 6 rays, closely connected, the posterior and larger portion more than twice length of head, 
reaching nearly to caudal in the adult (Diiiiylopterus ); much shorter in the young ( Cephalacanthm ); 
these rays very slender, simple, far apart at the tip; ventral rays i, 4, the long fins pointed, their 
bases close together, the inner rays shortest; air-bladder with 2 lateral parts, each with a large 
muscle; pyloric ceeca numerous; vertebrae 9+13=22. Warm seas; the adult able to move in the air 
like the true ttying-fish, but for shorter distances. One genus and 2 to 4 species. 
Genus 221. CEPHALACANTHUS Lacepede. 
Characters of the genus included with those of the family. Four species known — ('. rol-iterns on 
both coasts of the Atlantic, C. spinarella in the East Indies, C. peterseni from Japan, and one from the 
Hawaiian Islands, East Indies, and Japan. 
Cephalacanlhus Lac6pede, Ilist. Nat. Poiss., III, 323, 1802 ( spinarella >. 
Dactyloplerus Lacepede, 1. c., Ill, 325, 1802 (pirapedu ml Hans) 
Gonccephalus Gronow, Cat. Fishes, Ed. Gray, 106,1854 ( macrocephalu8=volitans ). 
