PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM 217 



Synopsis. 



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

 with the distal ; pyloric ccEca developed (2). 

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

 Ist D. with few rays ; branchiae in 2^ pairs ; branchial arches unarmed ; 



skin with scattered spiuigerous scutellto Ceratiix^. 



Ceraiias. 

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

 and at right or acute angle with the distal; pyloric cojca 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 Oneirodin.^. 



Oneirodes. 



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



armed with dentigerous tubercles ; body with ecattered tubercular 



scutellie. 



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



articulation under or behind eye HiMANTOLOPniN.E. 



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



about 12 ? Himantoloplms. 



Ab. Body short oval : dorsal fin with 4 rays, and i)ectoral with about 

 17 Corynolophus. 



CEKATIIN^. 



Ceratiids with tbe body and head compressed; mouth with ir,oderate 

 and almost or quite vertical cleft; branchiae iu 2^ pairs; branchial 

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

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

 rays, i)laced quite far back of the head ; pyloric coeca developed (2;. 



CERATIAS.* 



Ceratiiues 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 {i. e., with about 



20 rays). 



Ceratias Holbollii. 



1844— Ceratias Ho;bollii Kroyer, Naturhist. Tids^krift, 2. raekke, b. i, pp. 639-649, 

 1861— Ceratias HolboUi GUiitlur, Cat. Fishes iu Brit. Mus., v. 3, p. 205. 



Ceraiias 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). 



ONEIKODIN^. 



Ceratiids with the body and head compressed ; mouth with moderate 

 and almost horizontal cleit; branchiaB in 2J pairs; branchial arches 

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



" ( <r(!tl:><, 'apariar, ov, p, one that lias liorns, in allusion to the frontal ray. 



