98 BRITISH PALASOZOIC FOSSILS. [Zoopuyra. 
the axis to the extent of this area, or two irregularly elongate unequal cells in a slightly oblique line 
from the axis to the wall of the inner area; outer area separated from the inner by a sharp distinct 
line on each side, and composed of much smaller and more highly curved vesicular plates, so that there 
are from five to seven small, nearly equal, rounded cells, extending in a line obliquely upwards and out- 
wards from the inner area to the outer walls of the tube; horizontal section, boundary or divisional walls 
thin, stars radiated with from fifty to fifty-five very thin lamellze, of equal thickness, but alternately long 
and short, the long reaching to the centre, the short barely entering the edge of the inner area; wea- 
thered surface, stars flattened, separated by a depressed line; inner area forming a gentle convex, oval, 
or circular boss, with the axis forming a short impressed line in the middle; the radiating lamellze exhibit 
numerous delicate curved interstitial plates in the outer area, but none in the inner area. 
This beautifully delicate species is the largest of the genus I am acquainted with, the usual width of 
the stars being seven lines, diameter of the inner area about two and half lines. It very frequently exhibits 
the young oval buds within the corners of the old stars, generally but one, very rarely two in a star. 
Position and Locality—Forms large masses in the carboniferous limestone of Derbyshire. 
Explanation of Figures —PI\. 3. A. fig. 6. Part of mass, natural size, from Derbyshire, shewing the 
weathered appearance of the stars (the impressed lines being the sites of the original coral which wore 
faster than the matrix); several of the stars shew young buds within their lengthened corners.—Fig. 6a. 
Do. Horizontal section of one star magnified two diameters, shewing the central axis, and the circular 
germ of a young individual within the area of the parent.—Fig. 64. Do. Vertical section magnified three 
diameters of one column and part of a second, to shew the thick solid divisional wall between them, the 
thick central axis, the broad transversely septate inner area, and broad vesicular outer one. 
NEMATOPHYLLUM CLISIOIDES (J/°Coy). PI. 3. B. fig. 2. 
Ref.—M°Coy, Ann. Nat. Hist. 2nd Series, Vol. III. p. 18. 
Sp. Ch.—Stars generally hexagonal, and averaging two lines in diameter: weathered surface, stars defined 
by a rather thick, prominent, crenulated divisional wall; outer area inclined downwards and inwards to form a 
shallow cup, in the middle of which the inner area rises into a conical tent-like boss, having the small flattened 
axis in the centre ; horizontal section, divisional lines of the stars thin, straight; ais thin, half a line wide; 
radiating lamelle thirty-six, thin, one-half extending in a flexuous manner from the walls to the centre, 
the intervening ones also flexuous but of irregular lengths, most of them reaching half-way; tranverse 
vesicular plates about two rows only at the circumference, few and delicate, if visible at all; vertical section, 
axis as in the other species; inner area very wide, of large, little-curved vesicular plates, inclining obliquely 
downwards and outwards; one or two (or most commonly one and half) lengthened irregular cells reach 
from the axis to the outer area; outer area very narrow, of small, much-curved vesicular plates, inclining 
very obliquely upwards and outwards, forming minute rounded cells about two in a row. 
This species much resembles some of the massive Astreoid Clistophyllic of Dana, by the conical 
tent-like aspect of the inner area within the cups or weathered terminal cells; the distinct flattened axis, 
resembling that of the other Nematophylla, will however distinguish it. The flexuous character of the 
radiating lamelle in the transverse polished section is remarkable. The Astrwa irregularis of Portlock’s 
Report on Londonderry, &c. which I know to be a true Nematophyllwm, resembles this species in the small 
size of the stars and flexuous lamelle, but is easily distinguished by the cells being simply cup-shaped, 
descending uninterruptedly from the walls to the small, flat, prominent axis in the bottom of the cup, 
instead of the large tent-like boss formed by the inner zone of the above species, 
Position and Locality—Forms irregular, tuberose masses in the carboniferous limestone of Derbyshire. 
Explanation of Figures.—P1|. 3. B. fig. 2. Natural size, shewing the form of the terminal stars — 
Fig. 2a. Do. Vertical section magnified three diameters, shewing the solid axis and the characters of 
the outer and inner areas, and giving the profile of the terminal star at top, shewing the narrow, steep, 
outer area, the wide tent-shaped inner area and the projecting axis.—Fig. 24. Do. Horizontal section 
