72 CALIFORNIA ACADEMY OF SCIENCES 



132. Oligoplites altus {Giinther). 



Plate XI, Fig. 20. 



One specimen taken in the Panama market. 



Head 4|^ in length without caudal; depth 3J. Eye 4^^ in head; snout 3^; maxillary i|. The 

 interorbital width equals the diameter of the eye. Dorsal V-I, 19; anal II-I, 20. 



Body moderately deep, as in specimens of O. sauries of equal size; contour very slightly 

 angulated at front of soft dorsal and anal. Mouth large, the maxillary reaching slightly past 

 eye. The bands of teeth on jaws are wider than in either O. sauries or O. miindiis, and differ from 

 them in having the outer row of the lower jaw composed of slender movable teeth which are more or 

 less in contact and project above the other teeth. They are bluntly rounded as viewed from the side, 

 but are laterally compressed to a sharp cutting edge. The width of the mandibular band of teeth 

 anteriorly is about a fourth of the diameter of the eye or one-fourth wider than ma.xillary near the 

 posterior end. The premaxillary band is somewhat narrower. The patch of vomerine teeth is 

 rounded in front and acutely pointed behind; its length about half the diameter of the eye, its width 

 about two-thirds of its length. The palatine patches are about half as wide as the vomerine patch. 

 Gill-rakers moderately slender, their length about two-thirds eye. Top of head and nape with pores, 

 as in O. mundus. Anterior branchiostegal rays connected across isthmus by a thin transparent 

 membrane. 



The anterior rays of dorsal are a little longer than those of anal. The last rays of dorsal 

 and anal are produced; those of anal a little longer, barely reaching to the short anterior caudal 

 rays. Pectoral about if in head; its tip reaching slightly past tips of ventrals. Origin of ventrals 

 nearer front of anal (behind detached spines) than tip of lower jaw by about half eye. Caudal lobes 

 subequal. 



Color not unlike O. mundus. Back slaty-brownish, lower parts and sides silvery. Top of 

 head to tip of snout dark; tip of mandible black. Pectoral fin dusky on inner face, growing darker 

 or black at base. Dorsal and caudal dusky, median rays of caudal darker at tips. Ventral and anal 

 white. 



This species differs from 0. mundus in having a smaller mouth, a more slender 

 body, and in the character of the teeth in the lower jaw. Dr. G. A. Boulenger has 

 kindly re-examined for us the type of 0. alius in the British Museum, and informs 

 us that the top of the head is densely beset with pores, and the anterior branchioste- 

 gal rays of the two sides are joined by membrane. There can be no question, there- 

 fore, as to the correct identification of our specimen. 



