3170 Bulletin 4.7, United States National Museum. 



Scales of moderate size, thin, not embedded, minutely ciliated; lateral 

 lines 2, the upper near base of dorsal, ceasing under origin of posterior fifth 

 of soft dorsal, the lower line beginning slightly in front of the end of the 

 upper line, running along middle of caudal peduncle ; the tubes very short, 

 borne on much smaller intercalated scales, and not forming a continuous 

 line; head largely scaled, the snout and jaws naked; gill-menibraues 

 united anteriorly, forming a narrow free fold across the isthmus; b ranch - 

 iostegals 7; pseudobranchhe well developed; a wide slit behind last 

 gill-arch ; gill-rakers short, broadly triangular, strongly toothed. Upper 

 margin of opercle, above its angle, wholly attached by membrance to the 

 shoulder girdle, as in the Rypticinae. Mouth large, protractile, the lower 

 jaw protruding, the maxillary broadly exposed, with a narrow supple- 

 mental bone along its upper edge. Teeth all villiform, in broad bauds on 

 jaws, vomer and palatines, the inner teeth on jaws slightly longer than 

 the others and depressible. Tongue smooth. Large mucous pores on under 

 side of mandible, and slit-like pores present on edge of preorbital and 

 around front of eye. Anterior nostril near edge of preorbital, provided 

 with a short tube; posterior nostril without tube or raised rim, immedi- 

 ately in front of eye ; a short free triangular flap on upper edge of each * 

 orbit. Upper portion of preopercle with a single strong plectroid spine, 

 directed backward and downward; bones of the head otherwise unarmed, 

 the preorbital and preopercle with entire edges, the opercle without spines 

 or ridges. Veutrals small and anterior in position, as in the Kypticinw, 

 consisting each of one strong spine, and five branched rays, their base 

 being in front of base of pectorals; no enlarged scale behind base of ven- 

 trals; 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 dis- 

 tinct subfamily, Rhegmatince. 



(ptfyjua, fracture; referring to the interrupted lateral line.) 



1615 (a.) RHEGMA THAOIASIUM, Gilbert, new species. 



Head 2^ in length ; depth 3; eye 5 in head; D. VII, 22; A. Ill, 18. Scales 

 45 in a longitudinal series along middle of side. Body elongate, moder- 

 ately compressed, with very short, deep, caudal peduncle; anterior pro- 

 file 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 entering the profile. 

 Dorsal spines low, strong, increasing backward, the last spine a trifle 

 longer than diameter of orbit; anal spines short and strong, tue middle 

 spine longest. Lateral line curved strongly upward from its origin to 

 below third dorsal spine, thence running 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 1 ase of pectoral ; 

 top of head scaled forward to interorbital space, the anterior scales here, 



