490 Memoir Sears Foundation for Marine Research 



apparently ready for birth, and a male, 270 mm. long, with the trifid tips of the claspers 

 fully differentiated (Harv. Mus. Comp. Zool., No. 36 104 to 36 11 6); a specimen 214 mm. 

 from the offing of Chesapeake Bay, Lat. 37° 24' N., Long. 74° 17' W. in 300 fathoms 

 (U.S. Nat. Mus., No. 26740). 



Distinctive Characters. Among northwestern Atlantic members pf the family this 

 species falls with Squalus acanthias, S. cubensis and Centroscyllium in its long and con- 

 spicuous fin spines. But it is easily distinguishable from all these by the striking dissimilarity 

 of the teeth in its two jaws. It has sometimes been confused with E. fusillus of the eastern 

 Atlantic, but it is distinguishable from the latter at a glance by the fact that the interspace 

 b«*een its pelvics and its caudal is at least as long as the distance from the origins of the 

 former to the tips of pectorals (considerably shorter than this in -pusillus and spinax). Its 

 relatively slender caudal further separates it from spinax. 



Description. Proportional dimensions in per cent of total length. Male, 225 mm., 

 from north coast of Cuba (Harv. Mus. Comp. Zool., No. 36105). Female, 230 mm., same 

 locality (Harv. Mus. Comp. Zool., No. 36104). 



Trunk at origin of pectoral: breadth 9.8, 10.4; height 7.1, 7.8. 



Snout length in front of: outer nostrils 2.7, 2.2j mouth lO.O, lO.O. 



Eye: horizontal diameter S-(>i 6.1. 



Mouth: breadth 7.6, 7.65 height 1.3, i.i. 



Nostrils: distance between inner ends 3.5, 3.0. 



Labial furrow length frotn angle of mouth: upper 1.8, 1.4; lower 1.8, 1.2. 



Gill opening lengths: ist 1.3, 1.3; 2nd 1.3, 1.3; 3rd 1.3, 1.35 4th 1.3, 1.35 5th 



1-3, I-3- 



First dorsal fin: vertical height 3.8, 2.8 ; length of base 5.8, 5.2. 



Second dorsal fin: vertical height 6.0, 5.2; length of base 8.9, 7.4. 



C««i«/^«; upper margin 21.3, 21.3; lower anterior margin 10.2, 9.6. 



Pectoral fin: extreme length 10.2, 9.6} extreme breadth 5.8, 4.8. 



Distance from snout to: ist dorsal 34.7, 34.85 2nd dorsal 58. 0, 60.O; upper caudal 



78.7, 78.7; pectoral 24.9, 23. i; pelvics 49.3, 50.O. 



Interspace between: ist and 2nd dorsals 19. i, 20.95 2nd dorsal and caudal 13.3, 



I3-9- 



Distance from origin to origin of: pectoral and pelvics 24.0, 26.9; pelvics and 



.caudal 28.8, 28.2. 



Trunk subcylindrical, moderately slender, its height at ist dorsal about Ve its length 

 to origin of caudal. Body sector to cloaca about i .3 to i .4 times as long as tail sector, without 

 mid-dorsal ridge. Dermal denticles minute, close-set, similar over body as a whole, thorn- 

 like, slender, moderately curved, tapering, their bases more or less stellate but concealed in 

 the skin. 



Head a little less than V3 (28 to 29%) of length to origin of caudal, flattened above. 

 Snout thick and fleshy at tip, its sides slightly concave at eyes, its anterior outline only 



