316 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



b. Preopercnlum unarmed. A single spine on operculum. Lateral line absent(i) 



i. Ventrals each a pair of filaments, closely united throughout, approximate. .MlXONUS 



B. Ventrals inserted on humeral symphysis. 



1. Lateral line continuous, indistinct. 



a. Ventrals a pair of simple filaments. 



i. Pseudobranchiae present Siijembo 



ii. Pseudobranchise absent Monomitopus 



2. Lateral line obsolete (in almost every case). 



a. Ventrals bifid filaments. 



i. Teeth in villifonn bands on jaws, vomer, ami palatines. Head strongly armed. 



•Eyes minute. Snout armed Acaxthoncs 



b. Ventrals simple filaments. 



i. Eye rudimentary or absent. 



* Body with small, deciduous scales. No lateral line. 



t Eye not visible externally. Villifonn bands of teeth on jaws, vomer, and 



palatines Typhlonus 



' * Body naked. Notochord persistent. 



t Eye visible through skin. A few fang-like teeth on vomer and mandi- 

 ble Barathronus 



ttEycnot visible. No teeth on maxillary or palatines. Rudimentary teeth on 

 vomer. Small teeth on mandible APHYONTJS 



C. Ventrals inserted under hyoid region. 



1. Ventrals long bifid filaments. 



«. Weak teeth, in jaws only ElIODICHTllvs 



D. Ventrals absent. (Uncertain as to family ami subfamily.) 



1. Eyes rudimentary. 



a. Head and bodj scaleless. 



i. Mouth vertical, vomer and palatines toothless Alexeterion 



2. Eyes developed. 



a. Head uncreated, scaleless. No lateral line. 



i. Villifonn teeth in jaws, vomer, and palatines. 

 *Fin rays very delicate. 1!. 8. 

 t (i ill-rakers almost rudimentary Hephthocara 



b. Head crested, scaly. 



i. Lateral line of large, specialized scales LAMPROGRAMMUS 



Genus BYTHITES, Reinhardt. 



Bythitts, REixnAUDT, Dansk. Vidensk. Selsk. Af hand!., vli, is ;s. 178.— GOnther, Cat. Fish. Brit. Mns., iv, 

 :;7."i. — Gill, Proc. Acad. Nat. Sci. Phila., 1863, 253.— Jordan and Gilbert, Bull, xn, LT. S. Nat. Mas.. 795. 



Brotulids having the body elongate, covered with minute scales, and with lateral line 

 interrupted over the vent. Head thick, naked, with cirri; month large and jaws equal. 

 A small spine at the angle of the operculum. Teeth in bands on jaws, vomer, and pala- 

 tines. Eye moderate. Vertical fins continent; ventral tins, a pair of bifid filaments, each 

 composed of two rays closely united nearly to the tip. Branchiostegals 8; gill mem 

 branes closely united, free from the isthmus. Air bladder large. Two pyloric caeca. No 

 barbel. A thick, conical anal papilla (in the male). 



BYTHITES FUSCUS, Reinhardt. 



Sythites fasom, Reinhardt, Dansk. Vidensk. Selsk. Afhandl., vil, 1838, 17!i, pis. vn-vni. — GOnther, op. 

 cit., 375. 



A Bythitts, having a body somewhat compressed, lipariform, its height about 4A times 

 in its length. Head thick and huge, its length more than one-fourth that of body, with 

 obtuse snout, naked, with minute cirri. Mandible, long, curved; it extends far behind 

 vertical from posterior margin of orbit. Eye small. Scales moderate, on body. Lateral 

 line complete, but interrupted over vent, the two parts slightly overlapping the same vertical. 

 Vertical fins confluent, enveloped in thick skin. Pectorals broad, lanceolate, with broad 

 base. Ventrals filiform, reaching behind origin of pectoral, as long as pectoral and two- 

 thirds as long as head. A conspicuous anal papilla in the male. 



The only known specimen, now in the museum at Copenhagen, was obtained in Green- 

 laud half a century ago. 



