1 64 Memoir Sears Foundation for Marine Research 



larger or smaller.*' Lower surface smooth, except along anterior part of tail where the 

 lateral bands of prickles encroach somewhat on the lower surface. 



A comparison of larger with smaller specimens shows that the total number of 

 large thorns (28-35) '" ^^^^ median row is established early, there being six from the 

 pectoral girdle to the level of the axils of the pectorals at the smallest size. There is 

 only one row along the tail on the smallest seen, but the lateral rows develop along 

 the posterior third when a length of about 300 mm is reached. These rows have ex- 

 tended forward to the level of the tips of the pelvics at a length of about 350 mm. 

 The thorns on the snout (lacking on smallest seen) are present at a length of 3 i 6 mm; 

 at first there are only two orbital thorns and one scapular on each side.*^ 



Snout in front of orbits about 3.0-3.15 times as long as orbit, its length in front 

 of mouth about twice as great as distance between exposed nostrils. Orbit about as 

 long as distance between orbits and about i .4 times as long as spiracle. First gill open- 

 ings about 22-23 °/o as long as breadth of mouth; distance between inner ends of 

 first gills about 2.0-2.2 times as long as distance between exposed nostrils, about 

 1.3— 1.4 times between inner ends of fifth. Nasal curtain and expanded posterior 

 (outer) margin of nostrils deeply fringed. Mouth, on females and immature males, a 

 little arched forward centrally; its shape on mature males not known. 



Teeth in 34-42 series in upper jaw, those of females close-set in quincunx, with 

 moderately high conical cusp; those of mature males not seen. 



Dorsals alike in shape and about equal in size, their bases confluent without 

 intervening thorn. Caudal membrane, posterior to second dorsal, about 80 "/„ as long 

 as base of second dorsal. Pelvics deeply concave outwardly, their anterior margin about 

 63-70 "/o as long as distance from origin of pelvic to rear tip; anterior lobe slender, 

 with three radials besides the first stout one and with rounded tip and deeply scalloped 

 rear margin; posterior lobe strongly and evenly convex, scalloped anteriorly but only 

 faintly wavy posteriorly; rear tip abrupt, extending about V4 of the distance from level 

 of axils of pectorals toward first dorsal. 



Anterior rays of pectorals extending forward about -\^ of distance from level of 

 fronts of orbits toward tip of snout. 



Color. Upper surface uniform grayish brown with greenish tinge (after many years 

 in alcohol), without definite markings; outer edges of pectorals and pelvics shading to 

 darker. Lower surface of disc and pelvics uniform chocolate brown, except for paleness 

 on jaws; lower surface darker than upper. Smaller specimens similar except for paleness 

 close over pectoral girdle; lower surface of tail paler chocolate brown. *^ 



81. The pelvics on a female about 357 mm long are prickly as above but they are smooth on all the others we have seen. 



82. There appears to be considerable variation, whether individual or geographic, in the stage at which the additional 

 large orbital and scapular thorns first appear. A male of 117 mm has two oculars and one scapular on each side; 

 an eastern Atlantic specimen of 184 mm (Holt and Byrne, Fish. Ireland Sci. Invest. [1906], 5, 1908: 57) had three 

 oculars and two scapulars on each side; a male, 316 mm, two oculars and two scapulars, one smaller, on each side; 

 a female about 350 mm (tip of tail damaged), three oculars on each side, two scapulars on one side and three on the 

 other; a female 463 mm (largest seen), five and six oculars, and three scapulars on each side. 



83. The lower surface of the type specimen from the Irish Atlantic slope is described as "brown, except the front of 

 the snout, mouth parts and belly" (Holt and Byrne, Fish. Ireland Sci. Invest. [1906], 5, 1908: 53). 



