64 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



Family BATHYPTEROID^^. 

 Bathypteroidcp, Gill, MS. 



Syuodontoideaiis witli tlie npper iioctoral ray entirely detached, thickened and devel- 

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



BATHYPTEROIS, Gunther. 

 Bathijptei-ois, Gunther, Ann. and Mag. Nat. Hist., 1878, 5th series, ii, 183. 



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

 with th(^ snout projecting, the large niandibh^ 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. Kays of the pectoral fin much elongate, some of the npjier 

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

 outer rays prolonged, 8 rayed. Dorsal fln 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 lamimc weU developed, 

 separate from each other; gill rakers long. Pseudobranchise 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 Bathyptehois 



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



length of fish) [B. longifilis, Gthr., Kermadecs.] 



B. Outer ventral rays prolonged (extending beyond anal). Uppermost pectoral rays not prolonged 



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



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

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

 (except in Ii. qiinihifilis) Subgenus SYNArTniSETMUS 



A. iVnal 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. 5!) 15. quadeii ills, Giiuther. Oft' Brazil. 



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



toral ray extending beyond caudal. A. 11; L. lat. 55. [B. Gi'iNTHEiti, Alcock. And.aman Sea.] 



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



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



B. Aual origin under middle rays of dorsal. Dorsal far back, far behind vertical from axis of ])ectorals. 



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



P. 2-17-8 B. lonoipks, Giinther. Offcast coast South America. 



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



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



BATHYPTEROIS DUBIUS, Vaillant. (Figure 74.) 



Bathyplcrois diibiiis, Vaillant, Exp. Sci. Trav. et Talis., I'oiss., 1888, 124, pis. ix, xii, figs. 4, 4a; pi. xiv, 

 lig. 4; 1)1. XV, figs. 4, 4(1, 4li. 



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 candal 

 one-fourth. Tiie eye is about one-sixteenth as long as the head; the interorbital .si>ace 

 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. 



