FAMILIES OF ACANTHOPTERI. 399 



tMoutli nearly vortical; aira' fiulonf;; 

 Avliolo head closely sealy. 



Priacaxtiiid^, 8() (/>). 

 tt Mouth nearly horizontal ; anal tin 



rather short Seruanid.e, 8(). 



WW. Maxillary with its upper edge for its 

 whole length slipping under the 



preorbital Spakid^, 88. 



RR. Anal fin elongate; pseudobranehije present; 

 spinous dorsal little developed. 

 X. Dorsal spines present; skeleton well 

 ossified. 

 Y. Pectoral fins broad, proeurrent for- 

 wards. 



t Body scaly ; slit behind fourth gill 

 small ; eyes superior. 



Ukaxoscopid.e, 103. 

 tt Body naked ; eyes lateral. 



TlUCIIODONTID.E, 10)^. 



YY. Pectoral fin narrow, not proeur- 

 rent; body scaly. 



Latilid.i:, 101 (/;). 

 XX. Dorsal spines obsolete ; skeleton 

 more or less cartilaginous. 



ICOSTKID/E, 101. 

 GKJ. GiU-membranes united to the isthmus, restricting the gill-openings 



to the sides. 

 Z. Body not elevated ; lateral lino 

 obsolete ; spinous dorsal short and 

 weak ; inner rays of ventrals long- 

 est GOBIID^, 104. 



ZZ. Body elevated; lateral line 

 present ; siiinous dorsal well de- 

 veloped (Chwtoilonlifonn lishes.) 

 a. Teeth setiform, in many rows ; 

 vertical fins densely sealy ; tail 

 unarmed. 

 b. Dorsal fin divided. 



EpiiirpiDyE, 97. 

 66. Dorsal fin continuous. 



Ch.etodontiDvE, 98. 

 aa. Teeth incisor-like, in one 

 row ; tail with 1 or more 

 spines on each side. 



ACANTIIUKID.E, 99. 



FF. Lower pharyngeals united. (PharyiKjof/uafhi.) 



c. Nasal openings single on each side; scales mostly ct(Mi(>id. 



d. Gills ;i-i, last slit small or obsolete ; psfnuhjbranchiic present; anal 



spines 2 Pomackn'tuiD/E, 90. 



(Id. Gills 4, a slit Ixdiind the last; pseudobrant-liiic obsoh^te; anal 



spines 'i or more.. -CichliD/E, 95. 

 cc. Nasal openings 2 on each side; anal spines :5; scah^s mostly cycloid. 

 e. Viviparous; dorsal fin with a scaly sheath; anal rays sK'iuler and 



numerous Embiotocidjs, 93. 



ev. Oviparous; anal rays rather few. 



