64 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



Family BATHYPTEROIDyE. 

 Bathypteroidw, Gill, MS. 



Synodontoideans with the upper pectoral ray entirely detached, thickened and devel- 

 oped as a tactile organ, extensible upwards. (Gill.) 



BATHYPTEROIS, Gunther. 



Bathypterois, Gunther, Ann. and Mag. Nat. Hist., 1878. 5th series, n, 183. 



Shape of the body like that of an Aulojnts. Head of moderate size, depressed in front, 

 with the snout projecting', the large mandible very prominent beyond the upper jaw. Cleft 

 of the mouth wide; maxillary much developed, very movable, much dilated behind. Teeth 

 in narrow villiform bands in the jaws; on each side of the broad vomer a small patch of 

 similar teeth; none on the palatines or on the tongue. Eye very small. Scales cycloid, 

 adherent, of moderate size. Eays of the pectoral fin much elongate, some of the upper 

 being separate from the rest and forming a distinct division. Ventrals abdominal, with the 

 outer rays prolonged, 8-rayed. Dorsal tin inserted in the middle of the body above, or 

 immediately behind the root of the ventral, of moderate length. Adipose fin present or 

 absent. Anal short. Caudal forked. Gill openings very wide; gill lamina? well developed, 

 separate from each other; gill rakers long. Pseudobranchia? none. 



ARRANGEMENT OF THE SPECIES OF BATHYPTEROIS. 



I. Outer ventral rays filiform, simple, their extremities soft, swollen, lamelliform. Anal far behind dorsal. 

 Dorsal origin over axis of vtntrals Subgenus Bathypterois 



A. Outer ventral rays not prolonged. Uppermost pectoral rays very elongate, biiid (longer than total 



length of fish) [B. Loxiill'll.is. Gthr., Kcrniadees.] 



B. Outer ventral rays prolonged (extending beyond anal). 1'ppcnnost pectoral rays not prolonged 



beyond caudal tip B. DIBITS, Vaillant. E. Atlantic. 



II. Outer ventral rays filiform, simple, prolonged, adpressed or inseparably united. End of dorsal and 

 origin of anal in same vertical or overlapping. Caudal with lower lobe usually prolonged 

 (except in li. quadrifilis) Subgenus Synapteretmus 



A. Anal origin in nearly same vertical as end of dorsal. Dorsal origin over axis of ventrals or nearly 



so. Ventral rays elongate. 



1. Ventral outer rays adpressed. Lower caudal ray not prolonged. Upper pectoral ray not extend- 



ing beyond upper lobe of caudal. A. 9; L. lat. 50 B. QUADRIFILIS, Giinther. Off Brazil. 



2. Ventral outer rays inseparably united throughout. Lower caudal ray prolonged. Upper pec- 



toral raj T extending beyond caudal. A. 11; L. lat. 55. [B. Gi ntiieki, Alcock. Andaman Sea.] 



3. Ventral outer rays coherent in basal half; two or three lower caudal rays prolonged. Upper pec- 



toral rays reach to adipose dorsal [B. lnsuiakum, Alcock. Indian Ocean.] 



B. Anal origin under middle rays of dorsal. Dorsal far back, far behind vertical from axis of pectorals. 



1. Uppermost pectoral ray as long as the fish, bifid toward its extremity. D. 13; A. 10; L. lat. 55; 



P. 2-17-8 B. LONGIPES, Giinther. Off east coast South America. 



2. Uppermost pectoral ray longer than fish, bifid from its middle. D. 12; A. 9; L. lat. 55. 



[B. longicauda, Giinther. Middle of Southern Pacific.] 



BATHYPTEROIS DUBIUS, Vaillant. (Figure 74.) 



Bathypterois dubius, Vaillant, Exp. Sci. Trav. et Talis., Poiss., 1888, 124, pis. ix, xn, figs. 4, 4a: pi. xiv, 

 fig. 4; pi. xv, tigs. 4, 4a, ib. 



This species does not appear to reach a large size; the largest of the many examples, 

 taken by the Talisman measuring 260 millimeters. The height is about one-eighth of the 

 total length; the thickness nearly one-twelfth; the head two- elevenths, and the caudal 

 one-fourth. The eye is about one-sixteenth as long as the head; the interorbital space 

 about equal to the distance from tip of snout to center of eye. Gill opening wide. Dorsal 

 origin a little behind origin of ventral, over about the seventeenth scale of the lateral line; 

 longest dorsal ray two-thirds length of head; base of dorsal a little less than its longest ray. 



