oe 
new Species of Monticuliporoid Corals. 339 
F.G.8., for a fine example of this species, from which the 
section figured on Pl. XII. fig. 1 6 was prepared. The species 
appears to be not rare in the Buildwas beds (Wenlock shales), 
where they crop out on the east bank of the Severn near 
Buildwas Abbey. It is associated in these beds with a rich 
Brachiopodous fauna, which has been worked out by Messrs. 
Davidson and Maw *. 
The two following species are contained in the collections 
of the British Museum (South Kensington), and the author 
has obtained Dr. Woodward’s kind permission to describe 
them. 
2. Amplewopora T microstoma, Foord. 
Corallum lobato-palmate, with a tendency to become ra- 
mose in some places. Surface with irregular swellings. 
Corallites prismatic, extremely slender, nearly straight in the 
axial region, but bending slightly towards the surface. No 
monticules are present, but the surface shows under a hand- 
lens small clusters of cells somewhat larger than, the average. 
Of these about three occupy the space of 1 millimetre, and 
about five of the smaller ones, so that the latter do not exceed 
zis inch in diameter. In rough fractures the walls of the 
cells are seen quite distinctly to be minutely crenulate, a cha- 
racter which occurs in so many species of the Monticuliporide f 
that its value for purposes of classification appears very ques- 
tionable. 
Microscopic characters.—Tangential sections show that the 
corallites are thin-walled, polygonal in outline, and very 
variable in size. The spiniform corallites are numerous and 
are observed at the angles of junction of the cell-walls, and 
frequently also in the substance of the walls between those 
angles. In this latter situation they give rise to an inflation 
of the walls of the cells. In longitudinal sections the tubes 
are seen to have thin walls, which are very slightly thickened 
* Vide Geol. Mag. new series, decade ii. vol. viii. p. 100 (Feb. 1881). 
+ This genus is defined by E, O. Ulrich (Journ. Cincinnati Soc. Nat. 
Hist. vol. v. p. 154, 1882) for the reception of such forms of the Monticu- 
liporid as possess the following characters :—a ramose, free, or incrust- 
ing corallum, composed of cells of one kind only, the walls as seen in 
microscopic sections being thin in the axial but thicker in the peripheral 
region, and being provided with straight tabule. Spiniform corallites are 
developed more or less abundantly in different species, to such an extent 
in some as to completely surround the cell-mouths. The geological range 
of the genus in the United States extends from the Cincinnati group 
(Caradoc) to the “ Sub-” Carboniferous (Mountain Limestone). 
t Crenulate walls are found in Monotrypa undulata, Nich., M. crenu- 
lata, Nich., Heterotrypa Dawsoni, Nich., and in the present species. 
