Zooruyva.] UPPER PALA®OZOIC RADIATA. 83 
diverging to the surface which they meet at nearly right angles; each tube towards its extremity ren- 
dered irregularly moniliform, by numerous, strong, unequal contractions nearly at the same level in adjoin- 
ing tubes; diaphragms about the diameter of the tubes apart, surface minutely granulose, marked with 
polygonal boundary walls of the tubes; each cell-mouth nearly closed by a concave diaphragm, perforated 
by a small, circular, central opening, about one-third the diameter of the tube; two circular openings 
sometimes seeming within the one polygonal boundary, owing to the unequal development of the boundary 
walls ; young interpolated tubes, few. 
Position and Locality—vVery common in the carboniferous limestone of Derbyshire. A small, more 
regular variety, with often hollow branches, common in the dark limestone of the Isle of Man. 
Subfamily. HALYSITINA. See page 26. 
Genus. SYRINGOPORA. See page 27. 
SYRINGOPORA CATENATA (Mart. Sp.) 
Syn. and Ref—Erismatholitus (Tubiporites) catenatus Martin, Pet. Derb. t. 42. f. 1. (not 2). 
Sp. Ch.—Corallum forming large masses of nearly equal, subparallel, very slightly diverging tubes, 
averaging half a line in diameter, and about their diameter apart, connected by nearly equal, transverse 
tubuli, slightly more than the diameter of the tubes apart, the origin of each producing a slight angular 
flexuosity in the main tubes ; tubular central opening rather large. 
This delicately formed species, as here restricted, corresponds exactly to the first figure and first variety 
mentioned by Martin, but not to his second variety or figure, which belong to the S. reticulata (Gold.) 
Position and Locality—kIn the carboniferous limestone of Derbyshire. 
SYRINGOPORA GENICULATA (Phiil.) 
Ref—Syringopora geniculata Phill. Geol. York. Vol. II. t. 2. f. 1. 
Sp. Ch.—Corallum forming large masses, composed of slightly radiating, or nearly vertical, round, tubes, 
averaging one line in diameter, about half their diameter apart, slightly flexuous or geniculate at each of 
the connecting tubuli, which vary from one to one and half lines apart, and are less than one line in diameter ; 
surface smooth. 
The very numerous short connecting tubuli, and the slight angular flexuosity of the main tube at the 
origin of each, give a very characteristic rugosity to this species, which frequently forms masses of great 
extent. 
Position and Locality—Abundant in the carboniferous limestone of Derbyshire. 
SYRINGOPORA RAMULOSA (Gold.) 
Ref.—Gold. Pet. Germ. t. 25. f. 7. 
Sp. Ch.—Corallum forming very large masses, of radiating, thick, gently flexuous, nearly smooth tubes, 
forking with nearly equal branches at long irregular distances ; average diameter of main tubes one and half 
lines ; connecting tubuli thick, varying usually from three to five or six lines apart; main tubes varying, from 
their flexuosity, from a little less than their diameter (the average) to two or nearly three times their diameter 
apart. 
The great size and flexuosity of the tubes, and the irregular distribution of the thick transverse ‘ubuli, 
easily distinguish this species from the other carboniferous ones ; the internal vesicular lining to the walls, or 
very oblique funnel-shaped imperfect diaphragms, occupy nearly the whole cavity of the tube, leaving but 
a yery slender open median space; the mode of branching is remarkable from its resemblance to dichotomous 
fission, the parent and young being nearly of equal size, and nearly equally deflected from the original 
direction. 
Position and Locality —Common in the impure carboniferous limestone of the Isle of Man. 
M2 
