PONTASTER. 61 
Lith. Vid. Medd. 1871 (1872), p. 240; Moeb. §& Biitschli, TB. Comm. 
Kiel, ii. & iii. (1875) p. 148; Perr. Arch. Zool. v. (1876) p. 268 ; 
Kor. § Dan. Nyt Mag. xxiii. (1877) 3. p. 59; wd. Norske Nordhavs 
Asteroidea, (1884) p. 85. 
Pontaster tenuispinus, Sladen, Chall. Rep, Ast. (1889) p. 28. 
Pontaster tenuispinis, Bel’, Ann. § Mag. iv. (1889) p. 438 ; 7d. P. ZS. 
1892, p. 430, pl. xxvi. 
Pontaster tenuispinus, var. platynota, Sladen, Chall. Rep. Ast. (1889) 
» 29, 
Pontaster hebitus, zd. op. cit. p. 33. 
Pontaster limbatus, ¢d. op. cit. p. 35. 
The proportion of R to r of disk varies between 33 and 72; a 
very variable species in many characters. 
Disk and arms flat, but the depth of the side at the angle of the 
disk varies somewhat; the arms taper regularly and, as a rule, end 
in fine points. The bases of the arms on the dorsal surface some- 
times, but not always, marked by a perforated area (the “ papu- 
larium’”’), of an elongate lens-like form containing from about ten 
to twenty holes. The sides of the arms, above, bounded by a pretty 
stout superomarginal, which may, however, be so thin as to be 
merely a line on the upper surface. ‘There may be as many as 40 
superomarginals, and pretty constantly each carries a well-developed 
spine, the base of which is surrounded by a number of spinelets. 
A similar, or sometimes rather stouter, spine is borne by each infero- 
marginal, and one or more of the surrounding spinelets may be 
prominent on account of their length. The intermediate plates on 
the lower surface are, as a rule, thickly covered with spines, but in 
these last there are, at times, reductions. The spines on the ambu- 
lacral plates vary considerably in number and disposition, but the 
most usual arrangement appears to be a row of about six small 
sipnes along the groove, with one, two, or three larger spines set 
transversely. Pedicellariw present or absent. Delicate spines may 
sometimes be seen rising from the dorsal paxilliform plates. 
m= 105.103 Liss: 13x, [4s 14 s2h6'5 » 18; 
e=74; 47; 55; 49; 64; 72; 66; 61. 
Distribution. Both sides of North Atlantic, as far south as 
Scilly Islands ; Arctic Ocean, Kara Sea. 70 to 778 fms. 
a. Faeroe Channel, 365 fms, ‘ Porcupine’ Exp. (St. 65), 
b, c. Faeroe Channel, 363 fms. ‘ Porcupine’ Exp. (St. 54). 
d-f. Faeroe Channel, 540 fms. ‘Knight Errant’ Exp. (St. 8). 
g-t. Faeroe Channel, 608 fms. ‘Triton’ Exp. (St. 9). 
k. Faeroe Channel, 305 fms. ‘ Porcupine’ Exp. 
Lp. Otf Valentia, 100-150 fms. ‘ Porcupine’ Exp. 
g-w. S.W. coast of Ireland, 315 fms. ‘Flying Fox’ Exp. 
a—z. S.W. coast of Ireland, ?250 fms. ‘Flying Fox’ Exp. 
a'-d', 5.W. coast of Ireland, 90-400 fms. G. C. Bourne, Ksq. 
e'-h'. S.W. of Scilly Islands, 305 fms, ‘ Porcupine’ Exp. 
