400 CONTRIHCTIOXS TO NORTH AMERICAN ICHTHYOLOGY IV. 



/'. Tooth villiform ; premaxillaries extremely protractile; gills 4. a 



slit In-hind last: pseudobranchiiB 

 concealed UEUKID.I:, '. |% J. 



//'. Teeth not villiform; premaxillariea moderately protractile: gills 



3*; last slit obsolete: pseudohran- 



chia- well developed .LAHKID.i:. '-'-I. 



EE. Ventral fins, if present, with the rays in more or less than the normal 



number (I, 5). 



h. Anal I'm present. 



i. Body compressed and elevated; the scales very small, or none. 

 _;'. Dorsal spines indistinct. 



k. Ventral rays 4-G BHAMID.I:. 80. 



kh: Ventral rays about 15 LAMIMUDID.E, 78. 



jj. Dorsal spines well developed; ventral s rays about I, ? ./KNID.K, 81. 

 it'. Body not specially elevated. 



7. Ventrals thoracic (if present). 



m. Ventrals \vithiuore than 5 soft rays; scales ctenoid ; Load 



armed. 



n. Vent normal BEUYCID.K, 82. 



nn. Vent in front of ventrals; dorsal spines few. 



Al'IIKKlKlDKKIIXE, 83. 



mm. Ventrals few-rayed or wanting; scales small or wanting. 

 o. Upper jaw produced into a sword; dentition feeble; 



gills reticulated.. .Xiriiiin.i:, ?-J. 

 oo. Upper jaw not produced ; dentition very >,tnmg: body 



elongate Tuicim i:n> i , 7:;. 



II. Ventrals jugular (if present). 



p. Pseudobrancbiie present. (lilainiifonn fishes.) 



q. Dorsal with many spines, sometimes entirely spinous. 



BLKXNIIIVK, 113. 



qq. Dorsal with few spines or none, 

 s. GUI-membranes united to the isthmus. 



ZoAUCin/E, 115. 



8. Gill-membranes broadly united, free from the 

 isthmus; venlrals none. 



<'I>M;I:<H;AI>II>.K, 116. 



888. Gill-membranes separate, free from the isthmus. 

 /. Ventrals filamentous, at the throat ; jaws with 



teeth Orilll)Ill>.K, 118. 



it. Ventrals none; jaws toothless. 



AMMODVIM) .!:, G9. 



pp. Pseudobranchia 1 obsolete. 



M. Dorsal without distinct spinon- part. 

 r. Vent at the throat ; vent nils none. 



l'i i I:ASI I.IMIU:, 117. 

 rr. Vent posterior. 



ir. Scales cycloid; caudal I'm present. 



<;.\I>II>.K, 120. 



inc. Scales spinous, keeled; no caudal I'm; 

 the tail attenuate. 



MACi:ri;in.i:, 121. 



nn. Dorsal I'm with a distinct spinons part, 

 edinposed of a few spines; ven- 

 trals I, 'J; gills :?, the gill-mem- 

 branes broadly united to the 

 lathmus BATKACHID^E, 



