124 Mr. F. M‘Coy on some new genera and species of 
Sarcinula (Lamk.). 
? = Arachnophyllum (Dana). 
The corals of this genus are essentially composed of vertical, — 
cylindrical, transversely septate tubes, with radiating lamelle 
within, forming distant ‘circular cells without polygonal bounda- 
ries ; the tubes are imbedded in a uniform cellulose tissue, from 
which the buds or young tubes seem to arise whenever the di- 
stance becomes great between any two cells, but the young tubes 
do not seem traceable into the old. The coral referred to by 
Dana (Acervularia Baltica of Lonsdale in the ‘ Silurian System ’) 
as the type of his genus Arachnophyllum, I find to have the 
cell-tubes transversely septate, though not well shown in Lons- 
dale’s figure—the latter genus has therefore no peculiar cha- 
racters—the cellular structure of the rays being common to 
several corals. 
Sarcinula tuberosa (M‘Coy). 
Sp. Char. Corallum forming large shapeless masses, the upper 
_ surface covered with irregular tuberose projections, separated 
by flat or concave spaces, and each having a depressed tubular 
centre 1 line in diameter, average distance between the centres 
5 lines; from the margin of each centre about thirty slightly 
sigmoidal, very delicate lamine radiate to the adjoining ones, 
generally without interruption, the radii connected by nume- 
rous small transverse vesicular plates : vertical section, centres 
forming nearly vertical and subparallel cylindrical tubes, with 
close transverse septa, connected by exceedingly fine uniform 
cellulose structure, which seems formed of small depressed 
cells arranged nearly in horizontal layers with a double curve 
conforming to the projections of the surface : horizontal section 
shows the tubular centres connected by a minute uniform 
cellular structure with a scarcely appreciable radiation. 
This strongly resembles the so-called Acervularia Baltica of 
the ‘Silurian System.’ 
Rare in the carboniferous limestone of Derbyshire. 
(Col. University of Cambridge.) 
Sarcinula placenta (M‘Coy). 
Sp. Char. Corallum forming tabular masses about 1 inch thick ; 
under side with small, concentric, imbricating undulations of 
growth and radiating scratch-like strie; the upper and lower | 
surfaces parallel and flat, composed of vertical cylindrical tubes 
forming circular cells at the surface 1 line in diameter, and 
averaging about 2 lines apart ; the intervening space being flat, 
cellular, and obscurely radiated on the weathered surface by 
