376 ACANTHOPTERYGII. 



Family, XXXIX— TRACHYPTEEID^, i?^., Swainson.^ 



Tcenioidei, pt. Cuv. : Gymnetridm, pt. Swainson. 



Branchiostegals six : pseudobranchise present. Body elongated, and strongly compressed. Gill openings 

 wide : gills four. Eyes lateral. Cleft of mouth slight. Dentition feeble, A single dorsal fin occupying the 

 whole of the back, having a detached anterior portion, the whole composed of rays that are neither branched 

 nor articulated : anal absent : caudal not in the longitudinal axis of the fish, or else rudimentary : ventrals 

 thoracic Scales absent. Pyloric appendages numerous. Vertebrae many. Bones soft. 



Genus, 1 — Regalecus, Briinn. 



Gymnetrus, Bl. Scliii. 



Definition as in the family, likewise the ventral in the form of a single filament with a dilated extremity. 

 Caudal fm, if present, minute. 



SYNOPSIS OF INDIVIDUAL SPECIES. 

 1. D. 4-5/320. Silvery. Coromandel coast of India. 



1. Regalecus Eussellii, Plate LXXIX, fig. 2. 



Gymnetrus, Russell, Fish. Vizag. i, p. 28, pi. xl. 



Cfymnetrus EmssellU, Shaw, Zool. iv, p. 195, pi. 28 ; Cuv. and Val. x, p. 377. 



Xiphdothis Eussellii, Swains. Fishes ii, p. 46 ; Jerdon, M. J. L. and Sc. 18.51, p. 139 (not synom.) 



Hegalecus russellii, Giinther, Catal. iii, p. 311. 



B. V, D. 4-5/320, P. 11, V. 1, C. 4. 



Body lanceolate, sword form, smootli, without scales. Mouth small, oblique, jaws extractile, the upper 

 slightly the longer. Teeth — absent. Fins — four or five rays on the head at first 'distinct, subsequently uniting 

 and forming a long filament : second dorsal extends from the neck to near the caudal fin, the central rays the 

 longest. Pectoral short. Caudal distinct from the dorsal, consisting of four rays united into one filament. 

 Scales — absent. Colours — a pale silver, but the sUvering comes oS upon handling : dorsal fin with a 

 dark edge. 



The fish described and figured by Russell was captured on the outside of the surf at Vizagapatnam, 

 March, 1788, and does not appear to have been subsequently observed. 



Habitat — Vizagapatnam, grows to two feet eight inches in length. The figure is after Russell. 



* Swainson, 1839 (Pishes ii, p. 47) instituted this family : Giinther, 1861 (Catal. iii, 300) adoptee! the same name but omitted 

 any reference to Swainson, as a consequence the nomenclature (see Carus and Gerstaecker, Pisces, p. 546), has been erroneously credited 

 to the latter of those two ichthyological authors. 



