Zoopuyra.] UPPER PALAZEOZOIC RADIATA. 101 
distinguished by the small, but distinct, central axis visible in the transverse fracture, and further by the 
different disposition of the lamellz of the inner zone. The small size of the tubes, and less number of 
lamell:e, distinguish it from the Stylawis major. 
This is probably the Lithostrotion striatum of Fleming (Brit. Anim.), as he particularly says, “the 
rays of the star unite with @ small solid central axis;” I think, however, with Mr Lonsdale, that he is 
wrong in his references. I have, with great pleasure, dedicated the species to so admirable a naturalist, 
the extraordinary merit of whose writings on the British marine animals is well known to all who engage 
in the same laborious and difficult study. 
Position and Locality—Common in the carboniferous limestone of Derbyshire. 
Explanation of Figures.—PI\. 3. A. fig. 3. Portion of mass, natural size, from Derbyshire.—Fig. 3 a. 
Do. Horizontal section magnified three diameters, shewing the central axis and inner and outer area.— 
Fig. 36. Do. Vertical section magnified three diameters, shewing the central axis, the nearly simple 
inner area, and vesicular outer area; and the top giving a portion of horizontal section, shewing the 
relation of the two views. 
STYLAXIS IRREGULARIS (AZ/‘Coy). Pl. 3. A. fig. 5. 
Ref. and Syn.—Stylastrea irregularis M°Coy, Ann. Nat. Hist. 2nd Series, Vol. IIT. p. 9. 
Sp. Ch.—Corallum of polygonal five or six-angled tubes two lines in diameter, of such twisted and 
irregular upward growth that a vertical fracture frequently exposes a mixed appearance of outer walls and 
internal sections; outer surface longitudinally striated and transversely wrinkled by waves of growth; vertical 
section, inner area broad, regularly septate by nearly straight, equal, thick, transverse plates; outer area very 
narrow, composed of much-curyed vesicular plates, forming rather open rounded cells, in rows obliquely 
upwards and outwards, two or three in a row; horizontal section, central area smooth, surrounded by 
about thirty slightly flexuous radiating lamellze from the walls, fifteen of which are much shorter than the 
others; near the walls the radiating lamellz are connected by few, thick, vesicular plates. 
This species is remarkable for the peculiar, irregularly twisted, mode of growth of the columns, 
which, when the rock is compact, gives the mixed character to the fracture, seemingly between that of 
Lithostrotion (Strombodes) and Stylastrea. It is also remarkable for the nearly perfect transverse chambering 
of the central area. The small diameter of the tubes and few lamellee easily distinguish it from the other 
allied species. 
Position and Locality—Forms small masses in the carboniferous limestone of Derbyshire. 
Explanation of Figures—P1. 3. A. fig. 5. Portion of mass natural size from Derbyshire, shewing the 
very irregular mode of growth.—Fig. 5a. Horizontal section magnified six diameters, shewing the central 
axis and irregularly anastomosing lamellee.—Fig. 56. Vertical section magnified four diameters, shewing 
the central axis on the right, and part of the left column, the broad, transversely septate inner area, and 
narrow outer vesicular area, upper part of the left-hand column shewing a partially weathered section. 
STYLAXIS MAJOR (A/*Coy). PI. 3. A. fig. 4. 
Ref—-M°Coy, Ann. Nat. Hist. 2nd Series, Vol. III. p. 120. 
Sp. Ch.—Tubes averaging six lines in diameter, mostly hexagonal, external surface coarsely striated 
longitudinally, and transversely marked with strong curved irregularities of growth, the convexity of the 
curves upwards: horizontal section, sixty-three slender radiating lamellze converging from the walls towards 
the flat central style or axis, which is about one line in width; one half of the lamelle reach the centre, 
the intervening ones reach rather more than half way; outer area exhibiting numerous transverse vesicular 
plates between the radiating lamelle. Vertical section, axis straight, ribbon like, inner area broad, of 
slightly-curved vesicular plates, forming rows of lengthened irregular cells, extending obliquely downwards 
and outwards from the axis, about three in a row; outer area of rows of small, hemispherically-curved 
