744 ADDITIONS TO THE FAUNA OF LORD HOWE ISLAND, 



Scales moderate, cycloid, striated, deciduous. Lateral line obso- 

 lete. Head naked; muciferous cavities well developed. Mouth 

 terminal, with wide oblique cleft; jaws subequal. Premaxillaries 

 slightly protractile; maxillaiy exposed, spatulate, without odon- 

 toid process. No barbel nor cirri. Jaws with a band of villiform 

 teeth, widest at the symphysis; premaxillaries with several pairs 

 of strong, acute, conical teeth anteriorly behind the villiform 

 teeth; mandible with a series of enlarged trenchant teeth, which 

 are strongest and recurved along the sides; vomerine teeth in a 

 broad subcrescentic band, the inner series consisting of enlarged, 

 well separated teeth; palatine teeth in a broad, elongate band, 

 the inner series similarly enlarged. Nostrils inconspicuous, in 

 front of the eye. Eyes small, sublateral, anterior. Opercle with 

 a small spine. Gill-openings wide ; gill-membranes united 

 in front, free from the isthmus; six branchiostegals; no pseudo- 

 branchise ; gill-rakers short, claviform, few in number. Vent 

 in advance of the middle of the length. Genital papilla spine- 

 like, provided with a pair of curved claspers. One dorsal fin, 

 originating midway between the pectoral and the vent, and 

 terminating a short distance from the caudal ; anal originating 

 about the middle of the body and united by membrane to the 

 base of the caudal; dorsal and anal fins with the rays simple and 

 hair-like, their bases enveloped in thick skin; ventrals contiguous, 

 inserted a little in advance of the pectorals, each developed as a 

 long filament of two distally coalescent I'ays; pectorals moderate, 

 pointed, the middle rays the longest; caudal .small, obtusely pointed. 



Etymology: — 8is, two; ayKiarpov, hook: in allusion to the 

 pair of hooked appendages beside the genital papilla. 



Distribution : — Lord Howe Island. 



This genus differs from Dinetnatichthys in its strong dentition 

 and in its double-rooted ventral filaments. 



DiANCISTRUS LONGIFILIS, sp.nov. 



D. 62. A. 48. 



Depth of body 5, length of head 4 in the total length; width 

 of head t of its length, which is 2^ in the distance between the 



