202 



CALIFORNIA ACADEMY OF SCIENCES 



rays are present, four specimens liafe but a single ray each, while two specimens are 

 without any trace of a pectoral fin. A. Jischeri, based on a young specimen with one 

 pectoral ray, and S. panamensis, based on an adult specimen without pectoral, are 

 duplicated by our material, and are to be considered as synonyms of A. fonsecensis. 

 The best description and figure are given by Steindachner under the name of 

 S. panamensis. The figure should be reversed. 



The scales along the lateral line are 60 to 65 in number, not about 85, as 

 stated by Giinther. In ten specimens, the fin-rays run as follows: 



Dorsal . 

 Anal... 



57 

 43 



Measurements in Hundredths of Length without Caudal. 



Length without caudal in mm 



Head 



Snout 



Maxillary 



Eye 



Interorbital width 



Depth 



Depth of caudal peduncle 



Length of caudal fin 



Length of pectoral fin 



Longest dorsal ray^ 



Longest anal ray 



366. Achirus scutum {Giinther), 



Known only from Panama and the Gulf of Fonseca; not recognized until 

 now since the original description. We found the species abundant at Panama, 

 securing about thirty specimens, the largest 18 cm. long. 



The species is strikingly marked with numerous narrow gray bars on a dark 

 brown background, the bars varying in number from thirteen to twenty, often pursu- 

 ing a wavy course and forking or coalescing with adjacent bars in a most irregular 

 and intricate way. In some specimens, the irregularities are few in number. The 

 dorsal and anal are marked like the body, but the caudal is much lighter, crossed 

 by about four irregular dark bars which often break up into series of roundish spots. 



The pectoral is usually shorter than the eye and contains three rays, of which 

 the middle is the longest. In twenty-five specimens, eight were found with two rays, 

 and three with four rays. In five sjiecimens, the fin-rays are as follows: 



