REPORT ON THE ASTEROIDEA. 195 
b, Adambulacral armature with three spines in the second series. 
With an aboral line of spinelets on the infero-marginal plates. 
Actinal spinulation spatulate, obtusely rounded or pointed. 
Lateral spines cylindrical or slightly flattened : : P trregularis. } 
b. Four or five lateral spines in diagonal line. Outer spines of the adambulacra 
armature short, not broad nor flaring, placed diagonally. An aboral 
line of spinelets on the infero-marginal plates , : : - é pontoporeus. 
D. With no spinelets on the supero-marginal plates, excepting in some species a very 
small one on the first or first four or five plates in the interbrachial arc. 
a, With small spinelets on the first four or five plates. 
a, With four or five spinelets, A well-developed series of pseudo- 
pedicellarize . r . - . ° : F F é zebra. 
6, With one spine only, on the first plate. No pedicellaria . r velitaris. 
b. With no spines whatever on the supero-marginal plates, 
a, One lateral spine. 
a, With two or three spines in the second series of the adam- 
bulacral armature. 
i. Supero-marginal plates broad, with small granules, 
Paxille with five to eight granules (or spine- 
lets) on the central tabulum . 3 4 . granulatus 
ii, Supero-marginal plates narrow, with large granules. 
Paxille with one granule on the central 
tabulum , . : : 3 : A monacanthus. 
6. Lateral spines two, side by side. Infero-marginal plates covered 
with squamules. An aboral line of spinelets present. Lateral 
spines taper and pointed. Supero-marginal plates very broad . cingulatus. 
ce. Lateral spines four, in an oblique line. Spines of the adambulacral 
armature all cylindrical and taper. Infero-marginal plates with 
papilliform spinelets rather than squamules. No aboral line of 
spinelets, Supero-marginal plates not very broad , - . mesactus. 
Chorology of the Genus Astropecten. 
a, Geographical distribution :— 
ATLANTIC : Twenty-two species between the parallels of 70° N. and 40° 8. 
On the eastern side: Astropecten irregularis, off the coasts of 
Scandinavia and Britain; and in the Mediterranean (fide Marion). 
Astropecten serratus, off the west coast of France (this species is also 
reputed to be a Mediterranean form, but its claim to be so considered 
appears to be doubtful). Astropecten awrantiacus, Astropecten bispi- 
nosus, Astropecten jonstoni (= Astropecten squamatus, M. and '.), 
Astropecten pentacanthus, Astropecten platyacanthus, and Astro- 
pecten sprnulosus, in the Mediterranean. Astropecten aurantiacus also 
extends to the Canary Islands. *Astropecten hermatophilus, off the 
