1884.] NATURAL SCIENCES OP PHILADELPHIA. 315 



dorsal and ventral outlines very similar to each other. Profile 

 evenly convex (with curve a little shorter at occiput) to snout in 

 front of nostrils, where it descends almost vertically. A slight 

 depression on each side of head, above nostrils, which makes the 

 profile more trenchant at that place. 



Mouth not very small ; the tip of maxillary does not quite 

 reach vertical from front of eye ; its length about 4:^ in head. 

 The teeth of the lower jaw pass just behind those of the upper 

 jaw, when the mouth is closed. Eye small, 5:^ in head. Pseudo- 

 branchiae well developed. Gill-rakers weak and flexible, 12 below 

 the angle, the longest about | eye. Preopercle entire. Branchi- 

 ostegals 6. Pelvis not ending in a spine. No trace of ventral 

 fins. No pores along the base of dorsal fin. The soft dorsal and 

 anal fins similar to each other, except that the anterior rays 

 of dorsal are correspondingly higher than those of the anal. 



The dorsal spines are distant from each other, and quite 

 imbedded in the skin. The first spine is on the vertical above, 

 from upper part of gill-opening. Distance of first ray of soft 

 dorsal to tip of snout equals the depth of the body. Distance 

 from first ray to last ray of soft dorsal is contained 1| in length 

 of body. Distance of first ray of anal to tip of snout about 2 

 in length of body. Base of anal 2 in length of body. 



The mucus-pores on upper anterior part of head form a sort of 

 irregular network. A main branch arises a little anterior to 

 upper part of gill-opening, which sends off branches, extending 

 backwards almost straight, and parallel to each other. 



The greatest width of head 2 in its length ; the greatest width 

 of body (midway on a line from upper part of gill-opening to 

 base of last anal ray) 2| in head. Cheeks and opercles scaly. 



Color in alcohol blue above, with numerous round dark blue 

 spots, about ^ as large as eye ; below silvery. Below pectorals, 

 on anterior half of body, ai-e some irregular blue markings. 

 Pectorals blue ; caudal yellowish, with faint bluish shade on tips 

 of its rays. The pectoral fins are about as long as head. 



The above description was taken from a specimen in very good 

 condition, from Rio Grande do Sul, South America. The speci- 

 men is in the Museum of the Academy of Natural Sciences of 

 Philadelphia. It was originally sent there from the Museum of 

 Comparative Zoology. Length of specimen, 14 inches. 



