GILBERT AND STAEKS — FISHES OF PANAMA BAY 99 



Ventrals small and anterior in position, as in the Rypticina, consisting each of i strong 

 spine, and 5 branched rays, their base being in front of base of pectorals; no enlarged scale behind 

 base of ventrals. Vertical fins low, with rounded lobes, their basal portions well scaled; dorsal with 

 7 low strong spines and 22 profusely branched rays; anal with 3 spines and 18 rays. One species, 

 apparently the type of a distinct sub-family, RhegmatincB. 



179. Rhegma thaumasium Gilbert. 



Plate XV, Fiu. 31'. 

 Rhegma thaumasiuiu Gilbert, I.e., p. 3170. 



Head 2| in length; depth 3; eye 5 in head; D. VII, 22; A. Ill, 18. Scales 45 in a longitu- 

 dinal series along middle of side. 



Body elongate, moderately compressed, with very short, deep, caudal peduncle. Anterior 

 profile strongly arched, slightly depressed above orbits. Interorbital space very narrow, convex, its 

 width two-thirds diameter of orbit. Mouth large, slightly oblique; lower jaw the longer, its tip enter- 

 ing the profile. 



Dorsal spines low, strong, increasing backward, the last spine one-fourth longer than diameter 

 of orbit. Anal spines short and strong, the middle spine longest. 



Lateral line curved strongly upward from its origin to below third dorsal spine; thence run- 

 ning parallel with the back to below middle of second dorsal, from which point it gradually approaches 

 the base of the dorsal, where it terminates under the fifth ray from the last; along its anterior course 

 it is separated from base of dorsal by from 4 to 6 scales (in oblique series). Scales minutely ctenoid 

 except on head, breast, and belly, on nape under anterior dorsal spines, and on base of pectoral. Top 

 of head scaled forward to interorbital space, the anterior scales here, as well as those on cheek, much 

 reduced in size, embedded, so that their outlines cannot be distinguished. 



The following measurements of the type specimen are given: 



mm. 



Total length 85 Oue-bundredtbs 



° ^ ol length to 



Length to base of caudal 70 base of caudal. 



Greatest depth 33 



Least depth of caudal peduncle i Si- 

 Length of caudal peduncle 8 



Distance from tip of upper jaw to end of opercular flap 37 



Length of snout 6 



Diameter of eye 7! 



Interorbital width 3f 



Tip of snout to end of maxillary 19 



Length of pectoral 27 



Tip of snout to base of upper pectoral ray 35 



Tip of snout to base of ventrals 31 



Length of ventrals 13 



First anal spine 34 



Second anal spine 6 



Third anal spine \\ 



First soft anal ray , 84 



Longest soft anal ray 15 



First dorsal spine 4 



Last dorsal spine 9 



Longest dorsal ray 15 



Caudal 23 



