EcurnoperMarta. | LOWER PALXOZOIC RADIATA. 57 
hexagonal, and one pentagonal or heptagonal flattened plates, from which proceed two hands of three 
plates each (completing the cup) from whence the rays originate; one or two rows of large interbrachial 
plates between the secondary radial rows; a strong ridge runs up the middle of each of the primary 
.radial rows, then dichotomising, one branch going to each of the secondary radial or arm rows; all the 
plates of the cup marked with thick radiating ridges, one usually passing through the middle of each 
side to the centre of the adjoining plates; one large octagonal or hexagonal Ist interradial (or intercostal 
plate.) supporting two or three 2nd ditto (or interscapular plates); column rounded or subpentagonal, the 
joints radiated or marked with five petalloid crenulated ridges. 
Like Periechocrinus this genus has the plates of the arms and hands, or secondary and tertiary radial 
rows, flattened, to form part of the cup instead of the rays; the chief distinctions between these genera 
being the distinctly quinquepartite pelvis and strongly radiated plates of Glyptocrinus. 
GLYPTOCRINUS BASALIS (J/‘Coy.) PI. 1. D. fig. 4. 
Ref—M “Coy, Ann. Nat. Hist. 2nd Series, Vol. VI. p. 289. 
Sp. Ch.—Cup semipyriform ; pelvic plates hexagonal, slightly exceeding the primary radials in length 
and supporting the interradials on their upper truncated edge; all the plates marked with thick radiating 
ridges, one to each side, except in the pelvic plates, which have them only to the three upper sides, 
the lateral pair being the forked ends of the strong vertical ridge of the primary radial rows; average 
length of cup from pelvis to base of free rays, one inch six lines; width the same; length of pelvic 
plates three and half lines; pentagonal Ist primary radial three lines; hexagonal 2nd ditto two and half 
lines; heptagonal 3rd ditto (scapular) plate three lines; hexagonal Ist secondary radial or arm-plate two 
and half lines; 2nd ditto two lines. 
This fine species differs from the Glyptocrinus decadactylus (Hall.) of the Hudson River group of New 
York, by the great size of the pelvic plates, and their being hexagonal instead of pentagonal, and their 
bearing the interradial plate directly on their truncated upper edge, the interradial in the American species 
being supported on the sides of the laterally united Ist primary radials, which latter plates in this species 
are completely separated. The first of the secondary radial, or arm-plates, are laterally united without the 
intervention of an interbrachial plate, which exists, however, between the 2nd secondary radials, and nearly 
equalling them in size. In one of the most distinctly preserved interradial spaces, three 2nd interradials 
(interscapular plates) are seen to rest on the upper half of the octagonal Ist interradial, the lateral ones 
being pentagonal, and the middle longer one hexagonal. 
All the plates seem to have been thin and allow considerable variety in form of the cup from slight 
pressure. 
Position and Locality—Not uncommon in the calcareous schists of Alt yr Anker, Meifod, Montgo- 
meryshire. 
Explanation of Figures.—P|. 1. D. fig. 4. Natural size from the schists of Alt yr Anker, Meifod. 
Genus. EUCALYPTROCRINUS (Gold) 
= Hypanthocrinus (Phil.) 
Gen. Char.—Column and alimentary canal round ; body very large, oval, mouth central, projecting ; capital 
plates large, convex ; rays very short, only reaching to the base of the mouth; pelvis small, concave ; Ist 
primary radials five, hexagonal, each supporting a quadrangular 2nd primary radial, on which rests a 
pentagonal or slightly hexagonal 3rd primary radial (scapula), from the sides of which come off two rows 
of one or two secondary radials (arm-joints), often with one interbrachial plate between them ; each cuneiform 
secondary radial supports two free rays or hands, of two or more fingers, each finger of a double row of 
joints; five very large rounded polygonal Ist interradial plates, surrounded by the whole of the primary and 
secondary radials, supporting a pair of small ovate 2nd interradial plates, generally extending in a thick 
club-shaped ridge as far as the tips of the fingers. 
I 
