Fishes of the Western North Atlantic 1 6 1 



that are prickly (in addition to the large thorns) on R. bathyphila^ it is the upper surface 

 of the tail that is prickly on R. lintea. The lower surface of R. lintea, though it often 

 exhibits dark markings, seems never to be uniformly dark chocolate as on R. bathy- 

 phihiy except perhaps on some very small specimens. 



Actually, R. bathyphila more nearly resembles R.fyllae, apart from color, but its 

 snout is more acute and relatively longer than that of R./yl/iie; it has fewer large thorns 

 along the midzone of its disc rearward from the pectoral girdle; and the bands of prickles 

 along the sides of its tail are much denser and more conspicuous. 



Among Skates of the Pacific Coast of America, R. bathyphila parallels R. badia 

 Garman 1899 from the Gulf of Panama, R. trachura Gilbert 1892 from California to 

 Alaska, and R. abyssicola Gilbert 1895 from off British Columbia in the uniformly dark 

 color of its lower surface and in its abyssal habitat. But the shape of its disc marks it 

 off from R. badia (outer corners angular in badia and axis of greatest breadth far rear- 

 ward), and the presence of conspicuous thorns around its eyes and on its scapular 

 regions separates it just as sharply from both R. trachura and R. abyssicola. R. bathy- 

 phila has been characterized as "allied to Rata isotrachys^ Giinther 1877," which was 

 taken off" Japan by the Challenger in 365 fathoms and which is brownish black below. 

 But the original illustration of the unique specimen of R. isotrachys pictures it as re- 

 sembling R. badia more nearly than R. bathyphila in shape and as lacking large thorns 

 on the disc.'* Among the other deep-water Skates of the genus Raja from the western 

 Pacific-Indian ocean regions that are wholly or largely dark-colored below," R. bathy- 

 phila seems closest to R. mamillidens Alcock 1889 from the Gulf of Manaar in having 

 a small number of teeth, a generally prickly disc, and large thorns around the orbits, 

 on the scapular regions, and along the midline of the back from the nuchal region 

 posteriorly. But the snout of R. bathyphila is relatively much longer and the disc rela- 

 tively wider than these characters in R. mamillidens,^'^ while the teeth of the latter are 

 cuspidate even on small females (rounded in R. bathyphihi) and its color uniformly 

 black below as well as above. 



Description. Proportional dimensions in per cent of total length. Male, 328 mm 

 long, from Lat. 4i°28' N, Long. 65°3o' W (U. S. Nat. Mus., No. 148276). Female, 

 467 mm long, from Lat. 39°38' N, Long. 7i°i9' W (U. S. Nat. Mus., No. 35591). 



Disc: extreme breadth 49.4, 52.0; length 43.3, 44.9. 



Snout length: in front of orbits 11.3, 12.2; in front of mouth 12.8, 12.4. 



Orbits: horizontal diameter 3.6, ^t-^'-, distance between 3.3, 3.2. 



Spiracles: length 2.4, 2.6; distance between 6.4, 6.3. 



Mouth: breadth 4.9, 5.9. 



Nostrils: distance between inner ends 6.4, 6.1. 



77. By Garman, Mem. Harv. Mus. comp. Zool., 36, 1913: 329. 



78. Gunther, Challenger Rep., 22, 1877: pi. 3. 



79. For a recent survey of Indo-Pacific rajids, see Fowler (Bull. U. S. nat. Mus., 100 [/j], 1941 : 357). 



80. Length of snout in front of nostrils described as being only about as great as distance between nostrils for R. mamil- 

 lidens, the disc only about as broad as long (Alcock, Ann. Mag. nat. Hist., [6] 4, 18S9: 380; 111. Zool. Investigator, 

 Fishes, 1892: pi. 8, fig. i). 



