404 PROCEEDI]S"GS OF THE IS'ATIONAL MUSEUM vol.88 



referred to Apogon) ; lengtli of fin rays or presence of filamentous 

 rays; emargination of caudal fin. Probably some of these characters 

 are useful for generic diagnoses if used in conjunction with other fea- 

 tures. The presence or absence of palatine teeth and tlie union of the 

 first and second dorsal or the extent of the space between these fins 

 ap}X'ar to be highly variable, just as is the completeness or incomplete- 

 ness of the lateral line. In my opinion these variable characters, 

 among others, should not be relied upon as of generic significance 

 until tlieir constancy has been determined for each species in any 

 natural group. 



KEY TO THE GENERA OP CHEILODIPTERmAE 



Iff. Vent closer to base of pelvics than origin of anal fin. 

 2a. Anal rays III, 7 or 8 ; spines in first dorsal VII to IX ; a pair of enlarged 

 sympliyseal canines inside front e^gQ or margin of premaxillaries ; small 

 canines along front margin of premaxillaries, followed by a wide band 

 of villiform teeth posteriorly; sides of lower jaw with canines and with 

 1 or 2 pairs of enlarged canines near symphysis (fig. 19, a). 



Acropoma Temminck and Schlegel, 1842 

 2h. Anal rays II, 8 ; dorsal rays VI, I, 8 or 9 ; no symphyseal canines in either 

 jaw; small canines widely spaced on sides of upper and lower jaws; 

 }X»sterior half of upper jaw with a band of villiform teeth (fig. 19, /) ; no 

 palatine teeth ; vomer with teeth ; peritoneum silvery ; maxillary extend- 

 ing past rear margin of pupil Desmoaniia Fowler and Bean, 1930 



lb. Vent closer to origin of anal fin than base of pelvics. 

 ofl. Anal spines II. 



ia. No canines in jaws even at symphysis ; if teeth are present they are 

 villiform and in narrow to wide bands (fig. 19, li, i). 

 Ha. A thick silvei'y gland with black upper surface on each side of 

 base of tongue from which a broad silvery canal extends backward 

 on each side of isthmus to breast, then expands over base of 

 pectoral and covers lower portion of abdomen, thence runs back- 

 ward above base of anal fin to near base of caudal fin rays; 

 first dorsal VI or VII ; anal II, scales cycloid : lateral line 



complete or incomplete Sipliamia Weber, 1909 



5&. No silvery gland as above. 



6a. Anal rays II, 9 ; teeth if present villiform in one or two irregular 

 rows on jaws (fig. 19, Ji) ; operculum with 2 flat spines; pre- 

 operculum without double edge, the lower posterior angle much 

 produced and rounded; scale rows crossing lateral line about 

 .36 to 60; anus in front of origin of anal fin a distance equal 

 to or greater than diameter of pupil. 



Epig'onus Rafinesque, 1810 

 66. Anal rays II, 7 to 13 ; teeth villiform in wide baud on premaxillary 

 and a narrow to wide band on deutary (fig. 19, i) ; operculum 

 with 2 flat spines; preoperculum with double edge, posterior 

 one not produced but with contour similar to that of anterior 

 edge ; scale rows crossing lateral line fewer than 50 ; caudal fin 

 emarginate or rounded ; lateral line complete or incomplete ; 

 anus just in front of origin of anal fin or as far distant as 

 diameter of pupil Apog-on Lacepede, 1802 



