148 Memoir Sears Foundation for Marine Research 



2 b. Tail or disc posterior to pectoral girdle, or both, with few or many conspicuous 

 thorns; rostral projection from cranium firm, whether short or long. 

 3 a. Distance from origin of second dorsal to level of axils of pelvics longer 

 than distance from level of axils of pelvics to tip of snout by an amount 

 at least as great as distance between nostrils, or greater. 

 4 a. Either the tail with dark crossbars or the dorsal fins conspicuously 

 blackish, or both. 



5a. Upper surface of disc plain-colored; tail without dark crossbars. 

 Breviraja atripinna Bigelow and Schroeder 1950, p. 286. 

 5b. Upper surface of disc with dark markings; tail with dark 

 crossbars. 



6 a. Thorns on shoulders (2—4), along midline of disc, and on 

 anterior part of tail, large and conspicuous; anterior margin 

 of anterior lobe of pelvics as long as distance from origin 

 of pelvics to rear tip, or longer. 



Breviraja plutonia (Garman) 188 i, p. 297. 

 6 b. Thorns on shoulders (0—2), along midline of disc, and on 

 tail, small and inconspicuous; anterior margin of anterior 

 lobe of pelvics shorter than distance from origin of pelvics 

 to rear tip. 

 Breviraja cubensis Bigelow and Schroeder 1950, p. 293. 

 4 b. Neither the tail with definite dark crossbars nor the dorsal fins 

 blackish. 

 7 a. Midbelt of tail with 3—4 rows of conspicuous thorns. 



Breviraja sinus-mexicanus Bigelow and Schroeder 1950, p. 302. 

 7 b. Midbelt of tail with only a single median row of thorns. 



Raja fyl/ae^^ hiitken 1887; newborn, p. 194. 



Raja sema^^ Ga.rma.n 1885; newborn, p. 264. 



3 b. Distance from origin of second dorsal to level of axils of pelvics little if 



any longer than distance from level of axils of pelvics to tip of snout, 



and in most cases considerably shorter. 



8 a. Tip of firm rostral cartilage terminating considerably posterior to tip 

 of snout (Fig. 62).''" 



9a. Midzone of disc posterior to scapular region with only one or 

 two inconspicuous thorns, if any, in midline. 



Breviraja colesi Bigelow and Schroeder 1948, p. 289. 

 9 b. Midzone of disc posterior to scapular region with two to several 

 rows of thorns. 

 10 a. Snout anterior to orbits not more than about twice as 



59. It may be difficult in some cases to distinguish newborn specimens of K.fyllae and K. senta from each other. 

 See under Distinctive Characters, pp. 194-266. 



60. The point at which the rostral cartilage ends can be felt, if not seen, for all the species included under Sa. 



