No. 446.] ORAL BREATHING VALVES, OF TELEOSTS. 1 63 



Mand. V. covered with fine rounded papillae little 

 crowded, pigment in proximal half. . E. auritus 

 EE. Papills few. 



G. A few large papillae on Mand. V. along attachment: 

 central thickening extends through tooth pad and 

 half way to margin ; well pigmented. PapilFae 

 in Max. V. fine and well separated 



ChcEHobrytes gulosis 



GG. No papillae in Mand. V. Mand. V. well pigmented 

 at base, and meson quite black. Max V. well pig- 

 mented, especially between tooth pads. Papillae 



few and small Pomoxis sparoides 



Max. V. not extending between tooth-pads. 



[. Papillae in vertical, fold-like rows .... Apomotus pallidus 

 [H. Papill£E not in vertical, fold-like rows. 



I. Papillae of Mand. V. very few and flat, hard to see. Those 



of Max. V. blunt setiform. Mand. V. well pigmented on 

 proximal half Micropterus dolomieu 



II. Max. V. with fine, rounded, evenly distributed papillae and 



slight mesal thickening. Mand. V. with fewer and some- 

 what larger papillae; a few pigment spots on base at 

 meson extending through tooth-pads Eupomoius holbrooki 



ARGENTINID^. 



ves crescentic ; no papillae ; mandibular valve somewhat the larger, 

 lesal thickening on mandibular valve circular in shape and placed 



against attachment of valve, covering abbut h the width of the valve. 



Central third of maxillary and proximal half of mandibular valve 



pigmented Osmertis mordax 



No mesal thickening. 



Pigment spots near attachment of mandibular valve, few and 



