PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 217 



Synopsis. 



la. Mouth moderate ; cephalic spine with its basal element exserted and continuous 

 with the distal ; pyloric cceca developed (2). 

 2a. A second dorsal spine typically developed ; mouth with the cleft subvertical ; 



1st D. with few rays ; branchiae in 2| pairs ; branchial arches unarmed ; 



skin with scattered spinigerous scutellae Ceratiix^e. 



Ceratias. 



la. Mouth moderate ; cephalic spine with its basal element subcutaneous, procumbent, 

 and at right or acute angle with the distal ; pyloric cceca none. 

 2a. A second dorsal spine developed \ branchiae in 2\ pairs ; branchial arches un- 

 armed ; body naked. 

 3. Body and head compressed ; mouth with the cleft nearly horizontal, and 



mandibular articulation behind eye 'Oxeirodixje. 



Oneirodes. 



2. No second dorsal spine developed ; branchiae in $2} pairs ; branchial arches 

 armed with dentigerous tubercles; body with scattered tubercular 

 scutellse. 



3. Body and head compressed ; mouth with the cleft oblique ; mandibular 

 articulation under or behind eye HimantolophinJe. 



4a. Body oblong oval ; dorsal fin with about 9 rays, and pectoral with 

 about 12 ? Uimantolophus. 



4b. Body short oval ; dorsal fin with 4 rays, and pectoral with about 

 17 Corynolophus. 



CEBATIINiE. 



Ceratiids with the body and head compressed ; mouth with moderate 

 aud almost or quite vertical cleft; branchiae in 2J pairs; branchial 

 arches unarmed ; spinous dorsal represented by a rostral spine, as well 

 as, generally, by a second, whose basal element is exserted ; soft with few 

 rays, placed quite far back of the head ; pyloric cceca developed (2;. 



CERATIAS.* 



Ceratiines with an oblong form; skin prickly; vomer toothless; 

 cephalic spine elongated and with a simple capitate extremity; second 

 dorsal spine well developed, and pectorals multiradiate (*. e., with about 

 20 rays). 



Ceratias Holbollii. 



1844— Cera tics Holbollii Kroyer, Naturhist. Tidekrift., 2. raekke, b. i, pp. C39-G49. 

 1861— Ceratias Holbolli Giinther, Cat. Fishes in Brit. Mus., v. 3, p. 205. 



Ceratias with cephalic spine reclinable beyond base of caudal fin, and 

 caudal tin longer than body exclusive of head. 

 Deep sea along Greenland (known from several specimens). 



ONEIRODIXiE. 



Ceratiids with the body and head compressed ; mouth with moderate 

 and almost horizontal cleft; branchiaj in 2J pairs; branchial arches 

 unarmed; spinous dorsal represented by a (1) rostral spine, whose basal 



* Ceratias, Ktpanar, ov, />, oue that has horns, in allusion to the frontal ray. 



