40 DISCOVERY REPORTS 



Raja alba, Lacepede. 



1803, Hist. Nat. Poiss., v, p. 661, pi. xx, fig. 1; von Bonde and Swart, 1923, t.c, p. 5. 



Raja marginata, Lacepede, 1803, t.c, p. 662, pi. xx, fig. 2; Regan, 1908, Ann. Natal Mus., i, 



p. 242; Barnard, 1925, t.c, p. 65, pi. iv, fig. i; Clark, 1926, t.c, p. 47, pis. xxviii, xxix, 



XXX figs, a and b, xxxi fig. a. 



Disc broader than long, its width about f of the total length; anterior margins 

 undulated ; outer angles pointed. Vent about equidistant from tip of snout and end of 

 tail. Snout abruptly narrowed into a long sharp point, its length 4§ to 5I in width of 

 disc. Interorbital width about equal to diameter of eye + spiracle, which is 2 (young) 

 to nearly 3 in length of snout. Internasal width if (young) to 2 in praeoral length of 

 snout. Teeth with long conical points in the middle of the jaws, more obtuse and with 

 short points laterally; 40 to 46 rows. Upper surface quite smooth; one praeocular 

 and generally one postocular spine ; no nuchal or scapular spines, and no median spines 

 on disc; tail with a median series of 1 1 to 18 spines, extending forward to posterior end 

 of base of pelvic, and with a lateral series on each side. Lower surface with small 

 spines on the snout and along the anterior edges of the pectorals. Upper surface 

 uniformly brownish or more or less spotted with white; lower surface white, the tail 

 and margins of pectorals and pelvics often brownish or blackish, especially in the 

 young. 



Hab. Coasts of Europe, from the English Channel to the Mediterranean ; coasts of 

 northern and north-western Africa ; South Africa. 



Described from 12 specimens, 270-605 mm. in total length (205-465 mm. across 

 disc), from Kalk Bay, Simonstown, Agulhas Bank, Cape St Blaize, and off Bird Island, 

 Natal. 



Comparison of South African with European material shows that as a general rule 

 the snout is a little longer in examples from Europe, but this character appears to be 

 subject to considerable variation and I am unable to detect any other differences of 

 importance. Clark has shown that Lacepede's young black-bordered R. marginata is 

 identical with the white-bellied adult, R. alba, described by the same author. In 

 accordance with Article 28 of the International Rules, the name alba (p. 661) takes 

 precedence of marginata (p. 662). 



Raja rhizacanthus, Regan. 



Raja capensis {non Gmelin), Miiller and Henle, 1841, Plagiost., p. 151; Dumeril, 1865, Hist. 



Nat. Poiss., I, p. 540, pi. xii, figs. 11 and 12; Sauvage, 1891, Hist. Nat. Poiss. Madagascar, 



p. I ; von Bonde and Swart, 1923, t.c, p. 4. 

 ? Raja capensis, Kner, 1869, Reise 'Novara', Zool. i, 5. Fische, p. 419. 

 Raia rhizacanthus, Regan, 1906, Ann. Natal Mus., i, p. 3, pi. iii. 

 Raia clavata, Barnard, 1925, t.c, p. 64, pi. iv, fig. 2. 



Disc broader than long, its width f to ^. of the total length ; anterior margins more or 

 less undulated; outer angles pointed. Vent equidistant from tip of snout and end of 

 tail or a little nearer to the former. Snout with a short, obtuse, triangular projection, 

 its length 5j to more than 6 in width of disc. Interorbital width equal to or rather 

 greater than (a little less than in young) diameter of eye + spiracle, which is 2\ to 



