THE SUCKER FAMILY. 187 



sinuous brown bands so that it is more or less reticulated, and 

 m addition to the iridescent bluish bands just mentioned have 

 dots on the cheeks, bold touches of the same character along 

 the sides and at the base of the pectorals, the effect being 

 heightened by the orange tint of the inner surface of the 

 anterior rays. At 20 mm. when the lateral spines are de- 

 veloping, the pre-, post- and inter-ocular bands are still present 

 though the last (often greenish) is less distinct. Above 

 20 mm. the body (as at 25 mm.) becomes more uniformly 

 tinted, such as olive or bluish-green, the ocular belts, being 

 indistinct, but at the size just mentioned (25 mm.) the sides of 

 a green example are somewhat silvery, the first dorsal has a 

 brown tip, and the orange tint remains in the pectorals, thus 

 contrasting with the generally pale hue of the ventral surface. 



It is interesting that in these small forms slight pressure 

 causes the sucker to adhere in the dead animals. 



When 11 mm. long (in spirit), in June, it conforms rather to 

 the 20 mm. stage of Agassiz, since the first dorsal is long, 

 fleshy at the base, and with crenations for rays at the tip. The 

 breast-fins have increased in size, though they do not differ 

 much in their relations to the posterior border of the dorsal, 

 since that has been carried considerably backward by the 

 elongation of the fin. The second dorsal and the anal are 

 prominent, and the caudal has no trace of the larval tail. 



Little change ensues up to 17 mm., except the general 

 increase in bulk, the deepening of the first dorsal, and the more 

 evident crenations at the tip. When about 18 mm., however 

 (in spirit), four rows of simple papillae appear: — (1) A line of 

 minute and somewhat closely arranged papillae along the dorsal 

 ridge, and extending from the posterior part of the head to the 

 base of the first dorsal. Behind the latter, two rows occur, and 

 they cease before the commencement of the second dorsal. 

 (2) A line of small papillae extends from the tubular nostril 

 along each ocular ridge, and slopes downward along the dorso- 

 lateral region, but ceases opposite the first dorsal. (3) A 

 series of five larger, but still simple papillae, run from a point 

 above the base of the breast-fin to a vertical line from the 

 vent. (4) A similar number extend along each ventral edge 



