388 EEPUllT OF THE COMMISSIONER OF FISHERIES. 



3£easuremeJits. 



Some of the specimens were more or less imperfect, and Nos. 3 

 and 4 were so small that accurate measurements could not be taken. 

 The scales were not counted, except on the first specimen. The spec- 

 imens examined were taken by Mr. E. B. Forbes from a cave spring 

 in southern Illinois. 



Chologaster papiUiferus Forbes, American Nat., Jan., 1882, Cave spring in southern 

 Illinois. Jordan & Gilbert, Synopsis Fishes N. A., 325, 8U0, 1883. Jordan & 

 Evermann, Fishes North and Mid. Amer., 1, 704, 1896. Eigenmann, Proc. Ind. Ac. 

 Sci., 1897 (1898) 231; Degeneration in the Eyes of the Amblyopsidfe, its Plans, 

 Processes, and Causes, Proc. Ind. Acad. Sci., 1898, 239 (summary); Eyes of the 

 Blind Vertebrates of N. A., Archiv. f. Entwickelungsmech., 1899, 515; Marine 

 Biological Lectures, 1899 (1900), 113. 



Chologaster agassizii Putnam. PI. V, fig. 2. 



Body rather heavy but elongated, its depth 6 to 6.5 in length; head 

 3.50 to 4.33; mouth very oblique, lower jaw projecting, maxillary 

 reaching to the eye; eye very small and covered with skin, probably 

 only partially functional, located more on upper side of head than the 

 eyes of C. cornutus and C. iKipilliferm; gill-membranes joined to 

 isthmus, not covering vent; pectoral fin 1.40 in head; caudal rounded, 

 its length from base to tip less than head; dorsal with 8 or 9 rays, 

 somewhat rounded, inserted nearer base of caudal than tip of snout, 

 its front farther forward than front of anal; anal 8, smaller than 

 dorsal; scales similar to those of C. papUllferus; no tactile papillie 

 present. 



Since this species lives entirely in caves, it is much lighter in color 

 than either of the other 2 species of the genus. The myotomes are 

 very distinct, and form the 3 usual angles along the sides of the body. 

 The aponurotic septa, or lines between the myotomes, are dark, and 

 merge together to form a distinct dark line at the apex of the upper 

 angle. The apex of the middle angle is also visible for the same 

 reason, although this line is not so dark. The line along the apex of 

 the lower angle is nuu-h darker than that of the middle, but not so dark 

 as the upper. By the merging of these lines- 3 dark longitudinal lines 

 along the side of the body are formed, the upper darkest, the middle 

 one faintest but widest, and the lower one intermediate. Along the 

 back, beginning at the base of the caudal and coming to the point 

 just back of the head, is a yellowish line. The edges of the scales are 



