PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 227 

 NOTE OX THE C'EKATIffD^. 



By the:odohe gill. 



. Since the publication of the third volume of Giiuthers " Catalogno of 

 the Fislies in the British Museum" (1801), and the present author's Note 

 •on tbe Pediculati (18G3), the then monotypic family of Ceratiidce has 

 received notable additions, and this year (1878) one genus or rather type 

 of hitherto donbttui character has been substantiated, and two new allied 

 ones added. ±\\\ the representatives of the group appear to be inhabi- 

 tants of the deep or open seas. The relations of the genera seem to be 



approximately as follows: — 



Synopsis. 



la. Mouth iaod«'rate ; cephalic spine with its basal element exserted and continuoos 

 with the distal ; pyloric cceca developed (2). 

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

 Isl D. wiih few lays; branchiai in 2^ pairs; branchial arches unarmed; 



skin with scattered spiniyeroiis scntelliB Ceratiin^e. 



3a. A second dorsal spine developed, and fwo fleshy tubercles behind it ; pec- 

 torals with neatly 20 slender rays Ceralias. 



36. No second dorsal spine developed, but two fleshy claviforra tubercles exist- 

 ing i s in Ceiatias ; pectorals with about 10 slender rays Mancalias. 



16. Mouth moderate ; cephalic 8i)ine with its basal element subcutaneous, procumbent, 

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

 2a. A second dorsal spine developed; bianchisB in 2^ pairs; branchial arches un- 

 armed ; body uaktd. 

 3. Body iiud head comi^rossed ; mouth with the cleft nearly horizontal, and 



mandibnhir articulation behind eye Onkirodin^. 



Oneirodes. 



26. No second dorsal sp-ne developed; branchia) in ^2^ pairs; branchial arches 



armed wi.h deniigerous tubercles; body with scattered tuiercular 



scutella). 



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



articnhition under or behind eye HiMANTOLorniN.iE. 



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



about lit Eiviantolophus. 



46. Body .-^bort oval; dorsal tin with 4 rays and pectoral with about 17. 



CoryixoJophus. 

 36. Body and head depressed ; mouth with the cleft vertical or inclined for- 

 wards ; niandibnlar aiticulatiou under or in advance of snout 



^G^ONICnTnYINiE. 



.^^.gimnichthys. 



ic. Mouth enormous; (cephalic spine with its basal element subcutaneous, procum- 



lient, and at an acute angle with its distal?). 



2. No second dorsal spine developed. Mouth with the cleft subvertical. 1st D. 



with about 14 rays; branchiaj in 2^ pairs; branchial arches un 



armed ; skin naked MELAJioCETlNiE. 



Mdanocetm. 

 CEUxiTIlN^. 



CEUATIAS. 



Ceratias, Kroyer, Naturhist. Tidskrift, 2. rajkko, b. 1, p. 639; 1844. 

 Typo: C. Holbtilli Kroiitr. 

 Deep sea otf Greenland. 



