Fishes of the JVestern North Atlantic 



197 



toward tip; its length from center of cloaca to first dorsal greater than distance from 

 center of cloaca to tip of snout by a distance 1.5-3.0 times as long as horizontal dia- 

 meter of orbit in very young to medium-sized specimens and at least as long as distance 

 from center of cloaca to snout in adults; total length of tail from center of cloaca to 

 tip about 1.3— 1.6 times as great as distance from cloaca to snout in large specimens; 

 juveniles with tail perhaps averaging a little longer.^ 



Small specimens up to 90—100 mm long with a single median row of 30—40 

 large thorns on upper surface from nuchal region to first dorsal; 1—3 thorns on each 

 shoulder; 1—2 close behind orbit, with as many immediately anterior to it; a few smaller 



Figure 40. Raja fy/lae, same specimen as in Fig. 39. 

 A Posterior margin of nasal curtain, about 2.8 X. B 

 Nostril, about 3.6 X. C Upper teeth near middle of 

 jaw, about 7.2 X. 



ones near tip of rostral ridge; mid-dorsal row less regular with growth, 2—3 additional 

 rows developing irregularly along either side of it (no single row more conspicuous 

 than others); thus, typical adults are thorny along whole mid-dorsal belt of disc as well 

 as along upper surface of tail (Fig. 39), but some have midback thornless or nearly 

 so immediately posterior to shoulder region;* additional large thorns also developing 

 with growth over shoulder region as a whole, around orbits, and in 2—3 irregular rows 

 along rostral ridge; also a few developing in space between orbits in some specimens. 

 The outer posterior margins of the pectorals as well as areas of varying extent on either 

 side of the mid-dorsal belt continue thornless, but the anterior marginal regions become 

 conspicuously thorny by maturity in males, as is also the case in some females but not 

 in others (var. Upacanthd). A patch of large thorns also develops on the inner part of 



3. The relative length of the tail appears to vary considerably in half-grown and adult K.fyllae, to judge from published 

 photographs (Clark, Rep. Fish. Bd. Scot. [1926], i, 1926: cf. pi. 22, fig. a with pi. 24, figs, a, b). 



4. Described as a separate variety, Hpacantha, p. 198. See Clark (Rep. Fish. Bd. Scotl. [1926], i, 1926: pi. 24, figs. 

 a, b) for photographs of an adult male and female with thorn pattern of this sort. 



