40 



compressed; its greatest height, at the thoracic regiou, being a little less 

 than one-fourth (0.23) of the total length, and a little more than oue- 

 fonrth (0.27) of the length without caudal (0.89). In Eucinostomus aprion, 

 the most elongated of the species hitherto described, the greatest height 

 is but one-third of the length. 



The height of the body is uniform under the spinous portion of the 

 dorsal, slotting gently, and at a nearly uniform angle above and below, 

 to the middle of the caudal peduncle. The height of the body behind 

 the dorsal (0.10) is less than one-half, that of the least height of the tail 

 (O.OG) is one-fourth of the greatest height of the body. 



The scales are large, measuring 0.03 and 0.04 in height, and 0.02 and 0.03 

 in length ; they form about forty-five oblique transverse rows between the 

 head and the caudal, four and a half longitudinal rows between the 

 back and the lateral line, and ten longitudinal between rows the lateral 

 line and the belly. 



The length of the head (0.22) equals the greatest height of the body, 

 and is double the greatest width of the head (0.11); the height at the 

 jiupil (0.14) is double the width of theinterorbital space (0.07). The length 

 of the snout (O.OG) equals the length of the operculum (O.OG); when the 

 mouth is protruded, the length of the snout is doubled (0.12), and when 

 retracted, the posterior extremity of the intermaxillary process extends 

 to the vertical through the center of the pupil. The nasals are very 

 prominent, and the nostrils are nearer to the orbit than to the extremity 

 of the jaw. The orbit is circular, its diameter (0.08) one-third the length 

 of the head. 



The origin of the dorsal is slightly behind that of the ventral; its dis- 

 tance from the snout (0.31) twice the length of its base (O.IG). The dorsal 

 spines are graduated nearly in the proportion (1= 0.02; II = 0.12; III 

 = 0.11; IV = 0.10; Y = 0.09; VI = 0.085; VII = 0.725; VIII = 0.05; IX 

 = 0.04). The notch between the spinous andsoft portions is very deep, and 

 the connecting membrane barely perceptible. In the soft dorsal, the fifth 

 ray is the longest (0.09), and equals the fifth spine; the succeeding rays 

 diminishing regularly to the last, which equals the ultimate spine (0.04); 

 the length of its base (0.20) is greater than that of the spinous dorsals. The 

 anal begins behind the center of the body (0,5G); the first spine is very 

 short (0.01), one-fifth the length (0.05) of the second, which is slender; the 

 first ray is the longest (0.08) ; the succeeding rays regularly diminishing 

 in length to the last (0.03). The lobes of the caudal are equal ; the outer 

 rays in length (0.21) five times the inner ones (0.04). The extremity of 

 the pectoral reaches the vertical from the last dorsal spine; its distance 



