Fishes of tlie Western North. Atlantic 255 



Occurrence. It is known only from the northern and northwestern part of the Gulf 

 of Mexico, as listed in Study Material. 



Reference: 



Raja o/seni Bigelow and Sclirocder, J. Wash. Acad. Sci., 41 (12), 195 1 : 386 (descr., ill., Gulf of Mexico). 



Raja radiata Donovan 1807 



Thorny Skate, Starry Skate 



Figures c,K,, 56 



Study Material. Fifty-seven embryos and adults of both sexes, 126 to 935 mm 

 long, from: Norway; Egemonde and Tunugdliarfik Fjord, West Greenland; Grand 

 Banks of Newfoundland; Halifax, Nova Scotia; Emerald Bank, Georges Bank and 

 various localities within the Gulf of Maine, including the Bay of Fundy; off the con- 

 tinental slope from southwest of Georges Bank to New Jersey in 118-260 fathoms 

 and off South Carolina in 74 fathoms; in the U. S. National Museum and Harvard 

 Museum of Comparative Zoology. 



Distinctive Characters. R. radiata is marked off from all other Skates of the North 

 Atlantic by the large size of the thorns along the midline of the back from the nape 

 to the first dorsal fin, plus the facts that not more than 10 large thorns are present 

 on the tail posterior to the axils of the pelvics and that the anterior contour of the disc 

 is very obtuse (anterior angle at least 110°). It is so closely allied to R. doello-juradoi 

 of the Argentinian-Patagonian-Falklands region in the South Atlantic that no reliable 

 criteria have been found to distinguish the one from the other. 



Description. Proportional dimensions in per cent of total length. Male, 530 mm 

 (Harv. Mus. Comp. Zool., No. 249). Female, 800 mm (Harv. Mus. Comp. Zool., 

 No. 1 1 39), from Nahant, Massachusetts. 



Disc: extreme breadth 71.7, 74-5; length 52.8, 51.3. 



Snout length: in front of orbits 13.0, 12.9; in front of mouth 14.0, 13.9. 



Orbits: horizontal diameter 4.3, 3.8; distance between 5.1, 4.8. 



Spiracles: length 3.0, 3.3; distance between 8.1, 8.0. 



Mouth: breadth 10. i, 10.7. 



Nostrils: distance between inner ends 9.5, 9.8. 



Gill openings :\en^th?,, ist 1.9, 1.9; 3rd 2.1, 2.0; 5th 1.7, 1.9; distance between 

 inner ends, ist 17.0, 19.6; 5th 10.7, 12.2. 



First dorsal fin: vertical height 3.0, 3.2; length of base 5.2, 5.1. 



Second dorsal fin: vertical height 2.8, 2.8; length of base 5.9, 6.6. 



Pelvics: anterior margin 13.2, 11.2. 



Distance: from tip of snout to center of cloaca 49.4, 49.2 ; from center of cloaca 

 to 1st dorsal 36.5, 35.1; to tip of tail 50.6, 50.8; from rear end of 2nd 

 dorsal base to tip of tail 3.0, 2.8. 



Interspace between: ist and 2nd dorsals 0.5, 1.3. 



