^°189T''] PROCEEDINGS OF THE NATIONAL MUSEUM. 371 



Mouth terminal or subtermiual, with the cleft nearly horizontal. 



Jaics normally developed; intermaxillines with the aiscending pro- 

 cesses moderate, appressed and laminiform, separated by a shallow 

 cleft from the compressed lateral process ; supramaxiUines with the sella 

 extended mesiad behind and with the posterior limb expanded back- 

 wards into a lamelliform portion abruptly terminating in a pointed pro- 

 cess with an inward expansion. 



Teeth acute or tricuspid, present in the jaws and sometimes on the 

 palate. 



Lips rather thick. 



Tongue moderate. 



Suborbitals entirely concealed by the skin, consolidated and with the 

 third developed as a styliform stay connected behind with the outer 

 margin of the preoperculum. 



Opercular apparatus much reduced; operculum reduced to a bifid 

 plate, one fork curved backwards and the other downwards and for- 

 wards on a parallel with the preoperculum; siiboperculum a strap-like 

 piece under the posterior fork of the operculum ; interoperculum de- 

 tached, ray-like, and appended to the lower jaw. 



Freopercuhim with an upper portion expanded backwards and a lower 

 oblique bar like portion. 



Branchiotremes small and entirely confined to the sides above the 

 pectoral axillfc, the branchiostegal membrane being continuous with 

 the isthmus and scapular arch. 



Branchiostegal rays six on each side. 



DorsaUs entire, extending from near the nape backwards, with its 

 anterior rays developed as slender spines, and the posterior simply ar- 

 ticulated, but without external indication of the division. 



Analis elongate. 



Gaudalis supported by about eight to eleven rays without supplemen- 

 tary smaller ones, sometimes entirely free and in other species more or 

 less connected with the dorsal and anal fins. 



Pectorales with wide bases procurrent forwards and nuoierous rays, 

 the inframedian of which are sometimes much shortened, the posterior 

 borders being then emarginated. 



Ventrales modified to form a subcircular suctorial disk; the rays have 

 basal processes extending mesjad, appressed to the pelvic bones and 

 immovable; there are six on each side, mostly converted into osseous 

 tissue and not articulated. 



Branchice three and one-half to four, with the slit behind the fourth 

 obsolete or suppressed; gill-rakers moderate. 



SUBDIVISIONS OF LIPARIDID^. 



The family of Liparidids is represented by three well marked types 

 which deviate from each other in characters which are generally of 

 family value; that is, there is generally much less difference in the 



