18 
Indiana University Studies 
Gravid females show these minute specimens to be mature. 
Head 5.8 to 6 ; depth 4.5 to 5 ; D.8 ; A. 19 or 20 ; eye 2.8 to 
3 ; head flat and broad, the portion in front of the preopercle 
almost semicircular in outline, its width equal to its depth; 
the mouth inferior; the eyes lateral in position, located mid- 
way between the tip of the snout and the back of the head; 
width of fontanel slightly more than y.. of the width of the 
head, and its length almost twice its width, its area about 14 
the area of the dorsal surface of the head ; opercle with 8 
hooked spines, preopercle with the same number of similar 
but slightly weaker spines; the nares widely separated, the 
anterior separated from the posterior a distance equal to V 2 
the diameter of the eye ; the flap of the anterior nares prolonged 
into a barbel whose length is equal to 2 / 3 the diameter of the 
eye; two maxillary barbels, the outer slightly the longer ex- 
tending to the edge of the opercular flap; gill membranes 
united, free from the isthmus ; upper angle of the gill opening 
reaching to the lower edge of the base of the pectoral ; 
branchiostegals 6; gill rakers none; the maxillary teeth in 
three rows, directed backward, fine, long, and conical in shape; 
the origin of the dorsal over the origin of the anal, .7 the dis- 
tance between the tip of the snout and the base of the caudal ; 
the length of the longest ray slightly less than the length of 
the head ; the pectorals not near reaching the ventrals, the 
first ray half again as long as the last ; ventrals not reaching 
the anal opening; the anal truncate, the rays regularly de- 
creasing in length from the fourth ; the caudal lobed, the 
upper lobe slightly the longer ; the distance from the origin of 
the dorsal to the base of the caudal about three times in the 
length. 
Head, back, and sides with many black dots, those of the 
sides collected to form a lateral band extending from the head 
to the base of the caudal. A dark diagonal line extending from 
in front of the tip of the pectoral fin to above the anal opening. 
All fins irregularly covered with dots. 
Family Callichthyhle. 
Callichthys callichthys Linnaeus. 
17230, 21, 65-125 mm., Huachi. Aug., 1921. 
17231, 2, 67 and 80 mm., Ivon. Feb., 1922. 
17232, 8, 23-58 mm., Lagoons, Lake Rogoagua. Nov., 1921. 
