322 BULLETIN 10 0, UNITED STATES NATIONAL MUSEUM 



RHINOBATOS PETITI Chabanaud 



Rhinotatus (Rhinohatus) pctiti Chabanaud, Bull. Mus. Hist. Nat. Paris, ser. 2, 

 vol. 1, p. 365, fig. 1, 1929 (type locality: Madagascar, west coast, Nosy 

 Marirana Bank, between Ankilibe and Tulear). 



Snout elongate, obtuse, its end not expanded ; lateral edges partly 

 straight, slightly convex, level with nostrils. Rostral crests straight, 

 nearly in contact to middle, feebly dilated in front. Eye 7 in pre- 

 orbital, 4 in interorbital. Combined eye and spiracle % space be- 

 tween spiracles. Mouth little curved, width 2^3 in preoral length. 

 Nostrils long, oblique; internasal space l^ of nostril; anterior nasal 

 valve forms straight lobe. 



Body covered with extremely fine denticles, flat, and smooth above, 

 granular on rostral crests and middle of body, forming obtuse tu- 

 bercles on front and upper border of orbit; vertebral series of tu- 

 bercles present, also short series of 3 or 4 on each shoulder. 



First dorsal triangular, hind edge concave, front edge 1% in 

 preorbital length; second dorsal like first; caudal long and straight. 



Body above uniform reddish brown. Dorsals and caudal blackish, 

 except bases, hind borders, and angles. Below whitish. 



Length, 665 mm. (Chabanaud.) 



Genus APTYCHOTREMA Norman 



AptycJiotrema Noeman, Proc. Zool. Soc. London, 1926, p. 977. (Type, Rhino- 

 batiis {Syrrhina) hougainvilUi ("Valenciennes) Miiller and Henle. ) 



Differs from Rhinohatos in the nearly transverse nostrils, inward 

 extension of front nasal valve crossing inner angle of nostril and 

 absence of spiracular folds. 



Australia. 



ANALYSIS OF SPECIES 



a\ Snout ly^ to 1% in head measured to first gill opening; mouth, slightly 



curved; teeth subequal ; mouth width SM: in preoral length banksii 



a'. Snout lV-2 to 1% in head mea.sured to first gill opening; mouth well curved; 

 median lower teeth little enlarged ; mouth width 2*/^ in preoral length. 



bougainvillii 

 APTYCHOTREMA BANKSII (Muller and Henle) 



Rhinohatus (Rhinobatus) hanksii MtitLEu and Hhnle, Syst. Beschr. Plagiosto- 

 men, pp. 123, 192, 1841 (type locality: New Holland).— DuMfiRiL, Hist. Nat. 

 Elasmobr., vol. 1, p. 490, 1865 (Australia). 



Rhinohatus banksii Gunther, Cat. Fishes British Mus., vol. 8, p. 446, 1870 

 (compiled). — Hector, Colonial Mus. Governm. Suiw. Dept. (Fishes New 

 Zealand), p. 82, 1872 (compiled). — Macleay, Pi*oc. Linn. Soc. New South 

 Wales, vol. 6, p. 372, 1881 (Au.stralia; on Giinther).— Waite, Mem. Aus- 

 tralian Mus., vol. 4, p. 38, pi. 3, 1899 (New South Wales).— Ogilby, Com- 

 merc. Fish Fisher. Queensland, p. 46, 1915 (Moreton Bay) ; Mem. Queens- 

 land Mus., vol. 5, p. 85, text fig. 1 (left figure ventral view), 1916 (South 

 Hill, Moreton Bay, Cartwright Point, Low Blufi:, Double Island Point, 

 Hervey Bay, Hummocky Island, 7 to 24 fathoms). — McCulloch and Whit- 



