Zoopuyra.] LOWER PALALOZOIC RADIATA. 35 
fracture, as usual, passes through, and not between the columns, and the buds are developed in the corners 
of the old star. 
Position and Locality—Not uncommon in the Wenlock limestone near Wenlock, Shropshire. 
Explanation of Figures —Plate 1. B. fig. 28. Portion of large mass, natural size, from Wenlock.— 
Fig. 28a. Do. Vertical section shewing the strong divisional walls bounding the axis, the inner area, and 
the individual stars, as well as the peculiar tissues of each. 
Genus. ACERVULARIA (Schiveigger). 
Gen. Char.—Corallum of aggregated prismatic columns; terminal cells polygonal, defined by strong solid 
walls, convex, each with a circular depressed centre, from which the young cones sprout, from two to six, or 
more in number ; radiating vertical lamellze, of two sizes, the larger reaching from the walls to the centre, where 
they are simply united; no axis; vertical section, minutely and uniformly vesicular, the transverse rows of 
the outer area inclining upwards and outwards, those of the inner area curving under the centre, conforming 
to the surface of the star, a solid epithecal plate defining each star, and the tubular centre having also 
solid walls. . 
From the fissiparous mode of growth mentioned (that is, by the splitting of the centre) from two 
to seven or eight centres of radiation, or young cells, are frequently seen within the undisturbed circular 
boundary of the inner area of one star. The genus differs from Sarcinula by the solid epithecal boundary 
walls between the cells. 
ACERVULARIA ANANAS (Linn. Sp.) 
Syn. and Ref—Madrepora ananas (Linn.) Ameen. Acad. t. at p. 312. f. 9, 8, and 2. = Caryophyllia truncata 
(His.) Astrea ananas (Lonsd.) Sil. Syst. t. 16. f. 6. Lithostrotion Lonsdalei (D’Orb.) Prod. p. 48. 
Sp. Ch_—Corallum forming large tuberose masses, usually four or five inches in diameter, cells averaging 
four lines in diameter in the small variety, eight lines in var. major, varying between these in var. ramosa ; 
sex- to oct-agonal boundary walls, crenulated, prominent ; average diameter of circular inner area two lines, 
prominent edged, usually rather more than double the width of the outer area; outer area nearly horizontal, 
slightly concave ; inner area deeply concave, with a small prominence in the centre, produced by the meeting 
and slight twisting of the radiating lamell, which are thick, from forty-five to fifty in number, one half 
reaching the centre, the others barely entering the inner area; buds developed in the inner area from two 
to seven in number, separated by thick prominent ridges; vertical section shews a nearly uniform loose 
vesicular structure in both areas, the inner area and individual tubes being defined by solid walls. 
It is evident from Fougt’s reference to the small diagram, fig. 2 on his plate (representing excellently 
the cluster of buds arising solely from the inner area) that it is this present species alone which should bear 
the name Acervularia ananas. The Cyathophyllum ananas of Goldfuss seems to be a different coral, agreeing 
with the Devonian species figured under that name by Michelin. Fougt’s fig. 9 is no doubt different in 
size from the other two figures, but it is obviously generically different from the coral with prominent 
centres referred to it by Lonsdale under the name Acervularia Baltica, in the “Silurian System,” but it 
agrees well with a larger celled coral, apparently identical with the A. ananas in other respects, as mode 
of gemmation, number of lamelle, Gc. This might be referred to as a variety major. A more remark- 
able variety, and which has frequently been taken for a distinct species, is that in which the tubes form 
separate, rounded, very irregularly-ringed branches (well figured by Hisinger, t. 28. f. 14, under the name 
Caryophyllia truncata but not of Linné) ; in this also, however, the gemmation and number of lamelle is the 
same as in the two massive polygonal-celled varieties, and I have repeatedly noticed the two forms occurring 
together in one mass;—it might be called var. ramosa. 
Position and Locality Common in the Wenlock limestone of Dudley, Staffordshire ; also near Ledbury, 
Herefordshire. 
F2 
