356 BULLETIN 10 0, UNITED STATES NATIONAL MUSEUM 



Leucoraja Malm, Goteborgs Bohusl. Fauna, p. 609, 1877. (Type, Raja ful- 



lonica Linnaeus.) 

 Alpharaia Leigh-Sharpe, Journ. Morphol., vol. 39, pp. 567, 568, 1924. (Type, 



Raia circularis Couch, orthotypic.) 

 Betaraia Leigh-Sharpe, Journ. Morphol., vol. 39, pp. 567, 568, 1924. (Type, 



Raja clavata Linnaeus, orthotypic.) 

 Oammaraia Leigh-Shakpe, Journ. Morphol., vol. 39, pp. 567, 571, 1924. (Type, 



Raja hatis Linnaeus, orthotypic.) 

 Deltaraia Leigh-Sharpe, Journ. Morphol., vol. 39, pp. 567, 573, 1924. (Type, 



Raia radiata Donovan, orthotypic.) 

 Epsilonraia Leigh-Shaepe, Journ. Morphol., vol. 39, pp. 568, 574, 1924. (Type, 



Rata plat ana Giinther, orthotypic.) 

 Zetaraia Leigh-Sharpe, Journ. Morphol., vol. 39, pp. 568, 575, 1924. (Type, 



Raia l)rachyura Giinther, orthotypic.) 

 Etaria Leigh-Sharpe, Journ. Morphol., vol. 39, pp. 568, 576, 1924. (Type, 



Raja murrayi Giinther, orthotypic.) 

 Thetaraia Leigh-Sharpe, Journ. Morphol., vol. 39, pp. 568, 577, 1924. (Type, 



Raja eatonl Giinther, orthotypic.) 

 lotaraia Leigh-Sharpe, Journ. Morphol., vol. 39, pp. 568, 577, 1924. (Type, Raia 



marginata Lac6p6cle, orthotypic. ) 



Disk partly circular to quadrangular. Tail v^^ith fold along each 

 side. Snout more or less produced and pointed, with strong exten- 

 sion from skull as rostral cartilage. Eyes prominent, with fimbriate 

 velum above pupil. Mouth transverse, nearly straight. Teeth 

 small, tessellate, variably flat to sharply pointed. Nostrils with two 

 valves, front wide and reaches mouth, posterior folded in tube; 

 nasoral groove to each nostril. Gill openings small. Spiracles close 

 to eye. Skin usually more or less spiny. Caudal electric organs 

 often present or rudimentary. Two rayed dorsals on tail above. 

 Caudal membranous, rudimentary or absent. Pectorals widely sep- 

 arated at snout, not confluent. Ventrals notched. 



A large genus with many species, upward of 80 living and 25 

 fossil. Some of the living forms reach a width of 7 or 8 feet. Dis- 

 tributed in northern and southern hemispheres, many ranging into 

 deep water. The sexes are usually well differentiated. The males 

 are more spiny, with patches of erectile spines on the pectorals above 

 and with claspers, the last sometimes enlarged. Their coloration 

 closely resembles the sea bottom, on which they dwell. As they lie 

 concealed in the gravel or sand they await small marine animals, as 

 crustaceans, worms, squids, fishes, etc. Suddenly darting over their 

 victim and covering it with their wide body and fins, it is readily 

 devoured. The egg cases are quadrangular, each angle with a point 

 but without tendrils. The embryo leaves the egg soon after its 

 exclusion or even during its transmission through the cloaca of the 

 female. 



Baja punctata Woodward* is apparently a nomen nudum. 



« Western Australian Year Book, vol. 1, 1900-1901, p. 273, 1902 (Freemantle). 



