10 “TERRA NOVA” EXPEDITION. 
BATHYDRACONIDAE. 
Gymnodraco, with its depressed naked body, pointed snout, and compressed 
uniserial teeth with strong anterior canines, is connected with the genera with the 
body subeylindrical and more or less scaly, the snout spatulate, and the teeth 
villiform or cardiform, in bands, without canines, by the little known Parachaenichthys. 
ixamples of P. georgianus Fisch. recently brought back from South Georgia by Mr. P. 
Stammwitz, show that Parachaenichthys has nothing to do with the Chaenichthyidae, 
but is a member of the Bathydraconidae, with the depressed form and naked body of 
Grymnodraco, but the mouth and teeth of Bathydraco and its allies. 
In Parachaenichthys and Gymnodraco the feeble ribs are attached to the long 
epipleurals at some distance from the centra,* but in Prionodraco the ribs are stronger, 
are inserted directly on the short parapophyses and bear the epipleurals near their 
proximal ends. 
Prionodraco, Regan. 
Prionodraco, Regan, Ann. Mag. Nat. Hist. (8) xi, 1914, p. 13. 
Body elongate, compressed, quadrangular, with a series of V-shaped, serrated, 
bony plates at each angle; each plate with a backwardly directed spine. Lower series 
of plates ending in a group of nearly normal serrated scales behind pectoral fin ; 
usually a series of similar scales along middle of side; body otherwise naked. Lateral 
line single, incomplete. Snout spatulate; mouth slightly protractile ;. teeth small, 
villiform, in bands. Vertebrae 16 + 34. 
Prionodraco evansii, Regan (Pl. vu, fig. 1). 
Prionodraco evansii, Regan, Ann: Mag. Nat. Hist. (8) xi, 1914, p. 13. 
Depth of body 7 to 8 in the length, length of head 3 to 33. Snout as long as or 
a little longer than diameter of eye, which is 3 to 34 in length of head ; interorbital 
width 15 or more in length of head. Lower jaw a little projecting; maxillary 
extending to below anterior margin of eye. Operculum ending in a flat antrorse hook. 
He gill-rakers on lower part of anterior arch. Dorsal 34-37. Anal 29-31. Pectoral 
; to 4 length of head, extending beyond origin of anal; pelvics not reaching the vent. 
Caudal rounded or subtruncate. About 50 plates in upper series; lateral line ending 
below anterior part of dorsal fin. Dark spots on body ; usually a well-defined lateral 
series of large oblong or squarish spots; a blackish spot on base of anterior part of 
dorsal ; dorsal, caudal and pectorals with series of spots on the rays. 
al en specimens, measuring up to 132 mm. in total length, from the Ror Sea, 
74° 25'S., 179° 3’ E., 158 fathoms; and the entrance to MeMurdo Sound, 76° GIS), 
164° ie E., 160 Sia and 77° 13'S., 164° 18’ E., 207 fathoms. 
This species is named after Commander E. R. G. R. Evans, R.N., C.B. 
* As in the Gobiesocidae, which also have the body depressed. 
