Lake Maxlnkuckee, Physical and Biological Survey 445 



various intermediate values to 4.4 in head, and the end varies from 

 reaching to the anterior edge of the pupil, and the tip of the upper 

 jaw was on various levels, from the lower edge of the pupil to 

 the lower edge of the orbit. The number of scales covered by 

 the space between the spinous and soft dorsals varies from 1 to 

 about 4, and the space varies from 2 in ey€ through many inter- 

 mediate values to a trifle larger than the horizontal diameter of the 

 eye. Among our specimens is one which has the spinous and soft 

 dorsals continuous, the membrane being quite high throughout. 

 The dorsal formula of this specimen is XI, 10, and the cheeks and 

 opercles are naked. 



The color pattern is extremely variable; full notes on colors of 

 specific individuals are given below ; the following general re- 

 marks will serve to call attention to the great diversity : 



Aubeenaubee Darter (Ethcostoma aubeinuubei) 



A dark line downward from the eye and a dark heart-shaped 

 occipital spot (which is so frequent among fishes in general), ap- 

 pear to be always present. The color pattern of the caudal fin also 

 appears to be constant, at least so far as general effect is concerned, 

 though a study of more material might show a number of vari- 

 ations in detail ; it consists of a series of dark blotches, arranged in 

 irregular broken zig-zag bars. These probably vary somewhat in 

 number and position, their irregularity making it diflicult to cor- 

 relate them, giving thus a semblance to uniformity. The unit of 

 the pattern usually consists (in small, and presumably young, indi- 

 viduals) in its simplest form of a pair of parallel lines like the arith- 

 metical sign of equality — a bar on each side of the rays, the whole 

 making an elongate blotch from 2 to 4 times as long as wide, fol- 

 lowed by a colorless space of about equal length. Where the rays 

 fork there are likely to be three parallel lines; in the next stage of 

 development a row of dots is intercalated between the parallel lines; 

 these finally close up to form an entire line, and finally the whole 



