168 ECHINOIDEA. 
The smaller tubercles on the dorsal surface are very delicate, but 
not distinctly smaller close to than at a distance from the ambitus. 
The tubercles of the lower surface have the same general characters 
as in S. purpureus, but are not so large. 
Breadth of Breadth of 
Length. Breadth. Height. mouth. vent. 
100 94 55 18 85 
95 95 54 19°5 11 
90 88 63 175 55 
90 90 66 19 9 
70 68 40 a 8:5 
Distribution. Atlantie—Norway, Azores, Portugal, Agulhas Bank, 
Cape of Good Hope. 30(?)—200 fms, 
a, b. Off coast of Kerry, 100-200 fms. Royal Irish Academy. 
c-u, S.W. Ireland, 100, 110, 180 fms., July 1889. ‘ Flying Fox’ Exp. 
v. 54 miles off Achill Head, 500 fms. Royal Dublin Soe. 
w. 30 miles off Achill Head, 144 fms. Royal Dublin Soe. 
x,y. 45 miles off Blackrock, 500 fms. Royal Dublin Soe. 
z,a’, 40 miles off Bolus Head, 115 fms. Royal Dublin Soe. 
b'. Shetland. J.Gwyn Jettreys, Esq. 
4. ECHINOCARDIUM. 
Echinocardium, Gray, Ann. Phil. xxvi. (1825) p. 480; id. Cat. Brit. 
Rad. (1848) p. 6; td. Cat. Ree, Ech, (1855) p.42; Al. Ag. Rev. Ech. 
(1872) pp. 109 & 349; Carus, Prod. Faun. Mediter. (1884) p. 102; 
Dune. J. L. S. xxiii, (1889) p. 261. 
Spatagus (pars), O. F. Miill. Prod, Zool. Dan, (1776) p. 236. 
Amphidetus, 4g. Mém. Soc. Neuch. i. (1856) p. 184; [Amphidotus, 
Forbes, Brit. Starf. (1841) p. 190]; Ag. § Des. Ann, Sct. Nat. vii. 
(1847) p. 11. 
Test never large, rather thin, cordiform, truncated and highest 
behind ; the paired ambulacra triangular in outline, with few large 
pores; anterior ambulacrum in a groove, which may or may not be 
deep. Spines mostly silky. 
Key to the Species. 
a, Anterior ambulacrum in a groove. 
Antero-lateral ambulacra with, generally, 7 an- 
terior and 10 posterior -pores ; postero- 
lateral with 9 outer, and 8 or 9inner.... 1. E. cordatum. 
6. Anterior ambulacrum not in a groove. 
Antero-lateral ambulacra with, generally, 6 to 
8 and 12 to 15 pores ; postero-lateral with 
14 and IDM ere sss occa eee eee 2. E. pennatifidum. 
Antero-lateral ambulacra with, generally, 5 to 
6 and 9 to 10 pores; postero-lateral with 
Zand Gy kB Romat.(isce lk aanteoe en 3. E. flavescens, 
