306 ' AMEBICAN GAME. 



limb rising vertically forms a right-angle with the lower 

 one ; and its edge is armed with small spinous teeth, 

 those (m the lower limb being directed forward. The 

 bony operculum terminates in a narrow sub-spinous 

 point, beneath which there are three denticulations, with 

 grooves running backward from them. An acute- 

 pointed membranous flap prolonged from the margin of 

 the suboperculum conceals these parts iu the recent fish. 

 The edge of the interoperculum and posterior part of the 

 suboperculum are minutely denticulated. The edges of 

 the humeral bones are slightly grooved and denticulated, 

 the denticulations being more obvious in some individu- 

 als than in others. 



/Scales. There are sixty scales on the lateral line, and 

 twenty-two in a vertical row between the first dorsal and 

 centre of the belly. The scales are rather small, their 

 bases truncated and furrowed to near the middle (strikes 

 en eventaU) by six grooves corresponding to eight minute 

 lobes of the margin. A narrow border of the outer 

 rounded edge is very minutely streaked, producing teeth 

 on the margin, visible under a lens. The length and 

 breadth of a scale, taken from the side, are about equal, 

 being two and a half lines. A linear inch measured on 

 the sides or belly, longitudinally, contains twelve scales, 

 the scales on the belly having, however, less vertical 

 breadth. On the back an inch includes seventeen or 

 eighteen. The asperity of the scales is perceptible to 

 the finger, when it is drawn over them from the tail 

 12* 



