Fishes of the Western Nortfi Atlantic 281 



inner part of each pectoral. This in itself is enough to distinguish it (and ackleyi) from 

 all other Skates of the western North Atlantic, except for specimens oi R. ocellata which 

 are marked with one large ocellar spot on each side (p. 246). And the disc and tail of 

 R. ocellata are so much thornier than those of R. texana, and its anterior contour is so 

 much more obtusely rounded, that the two could hardly be confused. The only Skate 

 of the western South Atlantic that closely parallels R. texana (and R. ackleyi) in color 

 pattern is R. cyclophora Regan 19031*1 from Brazil, but the outer corners of the pectorals 

 of R. cyclophora are angular as contrasted with the rounded disc of R. texana. R. texana 

 is distinctive also in that the thorns on the mid-dorsal row are much smaller i*^ between 

 the pectoral and pelvic arches than they are forward to the nose and rearward along the 

 tail ; and, while the inner margins of the orbits are thorny, there are no thorns on the 

 shoulder regions. R. texana is closely allied to R. ackleyi (p. 155), but it appears to be 

 distinguishable from the latter by its relatively wider disc with abruptly rounded outer 

 corners (broadly rounded on R. ackleyi), by its color, the upper surface of its disc lacking 

 the small light and dark spots that mark R. ackleyi, and by the shape of the ocellar spots, 

 which are round in R. texana but oval in R. ackleyi. 



Description. Proportional dimensions in per cent of total length. Male, 293 mm, 

 from Freeport, Texas (Harv. Mus. Comp. Zool., No. 35845). Female, 387 mm, from 

 near Chauvin, Louisiana (Amer. Mus. Nat. Hist., No. 16351). 



Disc: extreme breadth 62.3, 64.2; length 46.1, 50.8. 



Snout length: in front of orbits 13.5, 14.5; in front of mouth 15.0, 15.5. 



Orbits: horizontal diameter 3.1, 3.4; distance between 4.8, 4.2. 



Spiracles: length 2.6, 2.3; distance between 6. 2, 6.1. 



Mouth: breadth 7.5, 7.5. 



Nostrils: distance between inner ends 8.0, 7.7. 



Gill openings: lengths, ist 1.2, 1.4; 3rd 1.5, 1.7; 5th 1.2, 1.2; distance between 

 inner ends, ist 14.7, 14.5; 5th 8.5, 8.0. 



First dorsal fin: vertical height 2.0, 1.8; length of base 5.8, 5.7. 



Second dorsal fin: vertical height 1.7, 1.6; length of base 6.1, 5.2. 



Pelvics: anterior margin 9.6, 10.3. 



Distance: from tip of snout to center of cloaca 44.7, 46.5 ; from center of cloaca 

 to 1st dorsal 37.5, 34.4; to tip of tail 55.3, 53-5; from rear end of 2nd 

 dorsal base to tip of tail 3.8, 4.7. 



Interspace between: ist and 2nd dorsals 2.2, 3.6. 



Disc about 1.2-1.3 times as broad as long; maximum anterior angle in front of 

 spiracles about 106° in smaller specimens, about 95° in half-grown, about 90° in adult 

 males, and about 85° in adult females; snout rather noticeably projecting, rounded at 

 tip; anterior margins weakly concave just posterior to tip of snout, then bulging slightly 

 and becoming weakly concave again opposite spiracles in both sexes; outer corners 



161. See Ribeiro (Arch. Mus. nac. Rio de J., 7, 1914: pi. 16) for photograph of R. cyclophora. 



162. On some specimens the thorns in the midrow may be absent for a short space about in hne with the two ocellar 

 spots. 



