278 DISCOVERY REPORTS 



St. 169. 22. ii. 27. 60° 48' 50" S, 51° 00' 20" W. Young-fish trawl, looo-iioo m. : i specimen, 

 69 mm. ? 



St. 245. 10. vi. 27. 38° 20' 00" S, 22° 18' 00" W. 4J m. net, horizontal, 1800-2000 m.: I specimen, 

 127 mm. 



Depth of body 5^ to 6| in the length, length of head 4J to 4I. Diameter of eye 2^ 

 to 2j in length of head, interocular width 3^ to 3 J, interorbital width about 6. Dorsal 

 9-10; origin a little nearer to end of snout than base of caudal. Anal 16-18; origin 

 nearer base of caudal than insertion of pelvic, 3^ to 3f times as distant from end of 

 snout as from base of caudal ; length of base 6| to 6| in that of fish. Pelvics 8- or 9-rayed, 

 inserted below middle or posterior part of dorsal. 37 to 41 scales in a longitudinal series. 



Described from five specimens, 69 to 185 mm. in length. In addition to the 

 Discovery material I have examined one other specimen, 152 mm. in length, from 

 51° 35' N, 11° 55' W, at a depth of 720 fathoms, lent to me by the National Museum 

 of Ireland. 



Hab. North and South Atlantic. 



Family GONOSTOMATIDAE 



MONOGRAPH OF THE FAMILY 



The Gonostomatidae represent the most primitive family of the sub-order Stomi- 

 atoidea, which is distinguished from the Clupeoidea by the presence of photophores. 

 According to Regan, ^ Photichthys, the most primitive genus, is very similar to Flops in 

 skeletal characters. The family may be defined as follows: — 



Elongate fishes, with or without scales ; mouth moderate or rather large ; suspensorium 

 generally directed more or less obliquely backwards. No special postocular luminous 

 organ, and no barbel. Gill-arches with gill-rakers. Dorsal fin in advance of or above 

 anterior part of anal, generally followed by an adipose fin; pectorals low, pelvics nearly 

 in the middle of the length. Skull elongate, with the parasphenoid nearly straight; 

 parietals well developed, meeting or approaching each other above supraoccipital ; 

 epiotics separated by supraoccipital ; basisphenoid and alisphenoids present ; no orbito- 

 sphenoid. Praemaxillary without anterior expansion; maxillary with two supplemental 

 bones. Post-temporal forked; mesocoracoid present. 



Fourteen genera, all of which are oceanic in habitat. 



Synopsis of the Genera 



I. Serial photophores on body arranged in continuous longitudinal rows; pseudobranchiae absent 

 or very feebly developed. (Gonostomatinae) 



A. A single series of photophores on each side of abdomen ; origin of dorsal fin nearly opposite 

 to that of anal. 



1. Origin of dorsal fin a little behind that of anal; no adipose fin; dorsal with 20 rays, anal 

 with 29 rays. i. Bonapartia 



2. Origin of dorsal fin a little in front of that of anal; adipose fin present; dorsal with 16 

 rays, anal with 23-26 rays. 2. Margrethia 



1 1923, Ann. Mag. Nat. Hist, (g), xi, p. 613. 



