154 ECHINOIDEA. 
wv". English Channel. Miss Buckland. 
y''. British Seas. Coll. Mantell. 
z''-d’, British Seas. 
6. Echinus elegans. (Plate XIV. figs. 3 & 4.) 
Echinus elegans, Dib. &§& Kor. Vet.-Ak. Hdlg. 1844 (1846), p. 272, 
pl. x. figs. 40-42; Ag. § Desor, Ann, Sct. Nat. vi. (1846) p. 365; 
Sars, Norg. Ech. (1861) p.94; Duj. § Hupé, Hist. Nat. Ech, 
(1862) p. 524; A. Ag. Rev. Ech. (1873-3 hie 122 & 491, pl. vii. a. 
fic. 4; Wy». Thoms. Phil. Trans. clxiv. (1874) p. 744, "pl. Ixviil. 
figs. 11-18; Al. Ag. Bull. Mus. C. Z. viii. isso} p. 77: id. Chall. 
Rep. (1881) p. 115. 
Test rather stout and rather high, sloping somewhat rapidly 
fromm apex to ambitus, flattened below. Primary spines of mcderate 
length, often with the appearance of being broken at their tips, 
much shorter below than above the ambitus, red in colour, except 
at the tip which is white; below the ambitus as much as or more 
than half the length of the spine may be white. Secondary spines 
of the same colour, numerous, rather delicate. Pedicellariza nume- 
rous, large, valves as much as 2-5 mm.long. Spines proportionately 
much longer in young than old forms. 
Peristome moderate, calycinal area not large, but madreporite 
very large and conspicuous. Primary tubercles more widely sepa- 
rated above than below the ambitus, and the secondaries much 
more numerous below than above it. 
In both ambulacral and interambulacral areze there is a con- 
spicuous median space devoid of all but small tubercles and bearing 
only small spines. About twenty-five plates in each interambu- 
lacral row ; the primary tubercle which occupies its centre is very 
conspicuous, has a wide spreading base, and stands well up; there 
are only a few secondary tubercles on these plates. The primary 
tubercles on the interambulacral plates diminish more rapidly in 
size towards the calycinal than the peristomial area ; at the ambitus 
they are quite prominent. 
All the radial plates are shut out from the periproct; there may 
be one, two, or three largish tubercles on the inner border of each 
interradial plate. 
Colour: the denuded test has a pinkish hue, of not so deep a red 
as in #. microstoma, and not so patchy as in #. norvegicus. 
Diameter of 
Diam. of Height of — 
—-—-— +. -—— ~ Longest 
test. test. Peristome. Calyc. area. = Periproct. spine. 
19 85 775 oo 
19 9 75 6 2:5 ie 
15 8 55 Bs 2 12 
12°5 35 6 ae 2 1 
9 4 375 3 1:5 10 
85 4 $3 2°75 15 
In drawing up this diagnosis much use has been necessarily 
