164 ECHINOIDEA. 
1. Schizaster fragilis. 
Brissus fragilis, Diib. § Kor. Vet.--Ak, Hdlg. 1844 (1846), p. 280, pl. x. 
fies. 47 49. 
Schizaster fragilis, Ag. § Des. Ann. Sct. Nat. viii. (1847) p. 22; Lrith. 
Vid. Medd. 1863 (1864), p. 175; Al. Ag. Rev. Ech. (1872) pp. 157 
& 363; Mob. § Biitschhi, JB. Comm. Kiel, ii. & iii. (1875) p. 150; 
Al. Ag. Bull. Mus. C. Z. (1880) p. 85; id. Chall. Rep. (1881) 
p: 201; td. Mem. Mus. C. Z. x. (1883) p.74, pl. xxviii. figs. 8-14; 
Rathbun, Proc. U.S. Nat. Mus. ix. (1886) p. 291. 
Schizaster (Brisaster) fragilis, Gray, Cat. Ech. (1855) p. 61. ; 
Tripylus fragilis, Sars, Norg. Ech. (1861) p. 96; Wyv. Thoms. Phil. 
Trans. clxiv. (1874) p. 750. 
Periaster fragilis, D’ Orbigny, Pal. Frange. vi. (1854) p. 270; Duj. § 
Hup. Ech. (1862) p. 598. 
Schizaster cubensis, Al. Ag. (non D’Orb.) Bull. Mus. C. Z, i. (1865) 
p. 278. 
Anterior ambulacrum not very deep; antero-lateral ambulacra 
about three times as long as the postero-lateral. Highest point of 
test in hinder third of body, whence there is a steep slope forwards 
and a very slight slope backwards. Mouth very far in front. 
General coloration of test in spirit brownish with lighter-coloured 
spines. 
emg thie tare arate ees cicteteucVoneetremnc terete: 45 53 51 
Greatest breadtly 9.1 je cie Gaertn ee ae 40 47 51 
Mele ht: 2.55 de ee, Barca a ad eee 24 29 27 
Length of anterior ambulacrum ........ 25 29 28 
Length of antero-lateral ambulacrum ....  .. 26 27 
Length of postero-lateral ambulacrum.... 5 10 11 
The only known British locality is that given by Thomson, “ at 
from 400 to 500 fathoms, between Scotland and Faeroe.” First 
reported from Norway, it has been taken at 50-452 fms. on North 
American coast, and at 150 fms. in Simon’s Bay. From each of 
these localities the Museum has specimens, but it has no British 
examples. 
3. SPATANGUS. 
Spatangus (pars), O. F. Miller, Prod. Zool. Dan. (1776) p. 286. 
Spatangus, Leske, Addit. (1778) p.171; Lamk. An. s. Vert. (1801) 
p. 348; Gray, Cat. Rec, Ech. (1855) p. 46; Desor, Syn. Ech. foss. 
(1858) p. 419; A. Ag. Rev. Ech, (1872) pp. 158, 564; Lovén, 
Vet.-Akad. Hadlg. xi. 7. (1874) pl. xxxvi; Carus, Prod. faun. Mediter. 
(1884) p. 102; Duncan, J. Linn. Soc. xxiii. (1889) p. 251. 
Echinus (pars), Pennant, Brit. Zool. iv. (1777) p. 58; L., Gmel. Syst. 
Nat. (1789) p. 3168. 
Test large, thin, cordiform, grooved in front, truncated behind ; 
the paired ambulacra petaloid, broad and sunken, the anterior and 
posterior pairs almost of the same length; the anterior ambulacrum 
in a groove, not well developed. Some of the tubercles much larger 
than the rest, and carrying long, strong, curved spines. 
The two species have very many characters in common, but 
