172 ECHINOIDEA. 
ambulacrum not in a groove, spines fine and delicate. Upper part 
of test nearly level from hinder end to the anterior border of the 
internal fasciole, and then sloping gradually downwards; the anus 
is slightly overhung by the upper part of the test ; the internal fas- 
ciole is well marked and is almost triangular in form, its hinder 
part is only one or two plates behind the madreporite ; the number 
of well-marked pores is, in the front antero-lateral series five or six 
and in the hinder nine or ten; the outer postero-lateral series has 
seven and the inner six; but, as before, too much importance must 
not be given to the constancy of these numbers; all the ambulacra 
are flush with the test. 
The long axis of the oval periproct is at right angles to a vertical 
line ; the subanal fasciole contains one or two pairs of pore-bearing 
plates; the bare ambulacral spaces below are very wide ; the tuber- 
culation is coarser at the sides and below than it is in the median 
part of the dorsal surface. 
Length. Breadth. Height. Peristome. 
3+ 33 23 vf 
24 20°5 16 5°5 
Distribution. Atlantic from Norway to Cape of Good Hope; 
North Sea; Coast cf Florida ; Mediterranean. 5-140 fms. 
a, b, 59° 34’ N., 7° 18' W., 542 fms. ‘Porcupine’ Exp., 1869. 
ce, d. Port Erin, Isle of Man. Prof. Herdman. 
e, f. Shetland. R. M‘Andrew, Esq. 
5. BRISSOPSIS. 
Brissopsis, Ag. Cat. Syst. Ectyp. (1840) p. 16 ; Ag. et Des. Ann. Set. Nat. 
viii. (1847) p. 14; Desor, Syn. Ech, foss. (1858) p. 878; Al. Ag. 
Rev. Ech. (1872) pp. 95 & 354; Dune. § Sladen, Pal. Ind. xiv. 3. 
(1884) p. 202; Dune. J. Linn. Sec, xxiii. (1889) p. 248. 
Brissus, orb. Brit. Starf. (1841) p. 187. 
Brissiopsis, Gray, Cat. Brit. Rad. (1848) p.7; id. Cat. Ech. B. M. 
(1855) p. 55. 
Kleinia, Gray, Ann. § Mag. vii. (1851) p. 183; zd. Cat. Ech. (1855) 
. 48. 
Pecabaeets) Des. Syn. Ech. foss. (1858) p. 399. 
Deakia, Pavay, Magyar foldt. intézet. Budap. Evk. iii. (1874) p. 804. 
? Verbeekia, Fritsch, Paleontogr. Suppl. ii. 1. (1877) p. 92. 
Test never large, rather thin, oval, somewhat compressed from 
side to side, truncated behind but not highest there; the paired 
ambulacra subpetaloid and sunken, the anterior pair as long or 
longer than the posterior, Anterior ambulacrum slightly sunken. 
Spines moderately stout. 
1. Brissopsis lyrifera. 
Brissus lyrifer, Forbes, Brit. Starf. (1841) p. 187 ; Diib. § Kor. Vet.- 
Akad, Hdig. 1844 (1846), p. 280, pl. x. fig. 46; Thompson, Nat. 
Hist. Irel. iv. (1856) p. 442. . 
srissopsis lyrifera, dg. § Des. Ann. Sci. Nat. viii. (1847) p. 15; 
Sars, Norg. Ech, (1861) p. 96; Du. § Hupe, Echin. (1862) 
