2 94 Memoir Sears Foundation for Marine Research 



405 fathoms,* in the Harvard Museum of Comparative Zoology; two specimens 

 trawled off St. Augustine, Florida, at 373 fathoms,^ in U. S. National Museum. 



Distinctive Characters. B. cuhensis falls with B. sinus-mexicanus, B. atripinna, and 

 B. plutonia because of the great length of its tail. But it is easily separable from B. sinus- 

 mexicanus by the facts that its tail posterior to the tips of the pelvics is not conspicuously 

 thorny, that it has only prickles and no thorns along its rostral ridge, and that the 

 prickles on its disc and tail are not densely pigmented. The dark markings on its disc 

 and the dark bars on its tail serve to distinguish it from B. atrifinna, which is plain- 

 colored. It resembles B. plutonia closely in general form, and some specimens have 

 much the same color pattern ; but the anterior lobes of the pelvics are relatively smaller 

 in B. cubensis than in B. plutonia (see Key, p. 148), the thorns on its disc are relatively 

 smaller, and usually there are only 1—2 thorns on either shoulder; the first and second 

 dorsals (confluent in B. plutonia) are usually separated by a definite interspace in B. 

 cubensis \ the teeth average a little more numerous in B. cubensis than in B. plutonia, 

 and the rostral cartilage is conspicuously longer, though intermediates may occur in 

 this respect. 



Description. Proportional dimensions in per cent of total length. Female, 203 mm 

 (Harv. Mus. Comp. Zool., No. 36445), and male, 210 mm (Harv. Mus. Comp. Zool., 

 type. No. 36443), from Cuba. 



Disc: extreme breadth 46.2, 49.7; length 37.1, 39-0. 



Snout length: in front of orbits 8.4, lo.o; in front of mouth 10.8, ii.o. 



Orbits: horizontal diameter 4.4, 4.8; distance between 2.8, 2.9. 



Spiracles: length 2.2, 2.4; distance between 6.7, 7.1. 



Mouth: breadth 5.7, 6.2. 



Nostrils: distance between inner ends 4.4, 5.0. 



Gill openings: lengths, ist i.o, 1.2; 3rd i.o, 1.2; 5th 0.7, i.o; distance between 

 inner ends, ist 10.3, ii.o; 5th 6.9, 6.7. 



First dorsal fin: vertical height 1.0; 1.2; length of base 4.9, 5.2. 



Second dorsal fin: vertical height 1.0, 1.7; length of base 4.2, 3.8. 



P^/wVj; anterior margin 10.8, 11.2. 



Distance: from tip of snout to center of cloaca 35.0, 38.1 ; from center of cloaca 

 to ist dorsal 50.8, 50.0; to tip of tail 65.0, 61.9; from rear end of 2nd 

 dorsal base to tip of caudal 2.5, 1.4. 



Interspace between: ist and 2nd dorsals 3.0, 1.4. 



Disc about 1.2-1.3 times as broad as long, obtusely rounded in front; tip of snout 

 marked by a low projection; maximum anterior angle in front of spiracles 115—130°; 

 anterior margin of disc rather strongly convex anterior to level of orbits and concave 

 opposite spiracles in most cases, more strongly so in males but more nearly straight 

 in some females; outer and posterior corners broadly rounded, posterior and inner 



4. Atlantis Sts. 2961, 2983, 2984, 2986, 2987, 2988, 2999, 3432, 3438, 3449, 3451, 3457, 3483> ^nd 34^5; fo'' P''^- 

 cise localities, see Chace (Contrib. No. 274, Woods Hole oceanogr. Inst., 1940). 



5. Albatross Sta. 2664. 



