316 DERP-SKA FISHES OF THE ATLANTIC BASIN. 



/). Prooperculuiu iiiKi-niiod. A siu^lo spine on opcrc-uluiu. Lntonil line al>a(int(?) 



i. VeutriilH ouch a pair of lilanunits, closely united throughout, approximate. .MixoNUS 

 H. Ventrals inserted on humeral synii)h,v8is. 



1. Lateral line continuous, indistinct. 



a. Ventrals a pair of simple filaments. 



i. Pseudobranohiai present Si hem no 



ii. PseudohranchiiB absent Monumitopus 



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



a. Ventrals l)ilid filaments. 



1. Teeth in villiform bands on jaws, vomer, and palatines. Head strongly armed. 



* Eyes minute. Snout armed Acanthonus 



b. Ventrals simple filaments. 



i. Eye rudiuumtary or absent. 



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



t Eye not visible externally. Villiform bauds of teeth on jaws, vomer, and 



palatines Typhlonus 



**Body naked. Notocliord persistent. 



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

 ble Barathhonus 



ttEye not visible. No tectli on uuixillary or palatines. Rudimentary teeth ou 

 vomer. Small teeth ou mandible Aph YoNu.s 



C. Ventrals inserted under hyoid region. 



1. Ventrals long bifid filaments. 



a. Weak teeth, in jaws only Ehodiciithys 



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



1. Eyes rudimentary. 



a. Head aud body scaleless. 



i. Mouth vertical, vomer aiul palatines toothless Alexeterion 



2. Eyes develoi)ed. 



a. Head uucrested, scaleless. No lateral line. 



i. Villiform teeth in jaws, vomer, aud palatines. 



* Fin rays very delicate. 15. 8. 



t Gill-rakers almost rudimentary Hepiithi )Caii A 



h. Head crested, scaly. 



i. Lateral line of large, specialized scales Lamprogrammus 



Genus BYTHITES, ReinharcU. 



Bythites, KTiiT^llARDT, Dansk. Videusk. Selsk. Af haudl., vii, 18.W, 178.— Gi':NriiER, Cat. Fish. Brit. Mus., i\', 

 375._GiiLL, Proe. Acad. Nat. Sel. Phila., 18G3, 253.— Jordan and Gilbert, Bull, xvi, U. S. Nat. Mus., 795. 



Brotiilifls having the body elonoate, covered with minute scales, and with lateral line 

 interrupted over the vent. Head tliick, naked, with cirri; mouth large and jaws equal. 

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

 tines. Eye moderate. Vertical flus confluent; ventral tins, a [);dr of Ijjlid lilameiits, each 

 composed of two rays closely united nearly to the tip. Branchiostegals <S; gill nicTii- 

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

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



BYTHITES FUSCUS, Reiniiardt. 



liythilcs fuscim, Rkinhardt, Dausk. Vidensk. Selsk. AfhanilL, vii, IS.SX, 170, pis. vii-viii.— GuNTHER, oj). 

 cU., 375. 



A Bythitcs, having a body somewhat compressed, lii);iriforni, its height al)out ii times 

 in its length. Head thick and large, 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 iiosterior margin of orbit. Eye small. Scales moderate, on body. Lateral 

 line complete, but interrui)ted over vent, the two parts slightly overlapiiiiig the same vertical. 

 "Vertical tins continent, enveloped in thick skin. Pectorals broad, lanceolate, with broad 

 base. Ventrals liliform, reaching behind origin of ])e('toral, as long as pectoral and two- 

 thirds as long as head. A con.spicuons ;iiial papilla in the male. 



The only known si)ecimen, uow iu the museum at Copenhagen, was obtained in (Srcen- 

 land half a century ago. 



