On a new Genus of Carboniferous Polyzoa. 43 
IV.—Note on a new Provisional Genus of Carboniferous 
Polyzoa. By R. Eruerripcs, Jun., F.G.S. 
[Plate IV. B. figs. 1-4.] 
HYPHASMOPORA, gen. nov. * 
Polyzoarium dendroid (?), calcareous, composed of small 
cylindrical stems, often bifurcating. Cell-depressions arranged 
in linear longitudinal series, more or less separated from one 
another by a cancellated network or reticulation, forming the 
interstitial surface, and predominating at one part of the poly- 
zoarium more than at others, presenting a longitudinal zone, 
devoid, or nearly so, of cell-depressions. The interstitial net- 
work consists of a series of irregularly formed pores. 
The fragments to which I have provisionally applied the 
above name consist of small occasionally bifurcating stems, 
with nearly the whole of the surface occupied by six or more 
longitudinal rows or series of pyriform and (for the size of the 
organism) large cell-depressions, subalternating one with the 
other. The intermediate and remaining portions of the in- 
terstitial surface, between each longitudinal series and each 
individual cell, are occupied by small, irregularly formed, but 
generally elongate pores, forming a reticulated or cancellated 
network. ‘This is more particularly the case over one part of 
the surface, generally devoid of cell-depressions, but occasion- 
ally with a single row running up the centre, or one or two 
irregularly placed. This space is bounded by the two lateral 
rows or series of cell-depressions, one occupying each side of 
the stem. At times the poral reticulation between the longi- 
tudinal series of cell-depressions is almost absent, or consider- 
ably reduced, when, the lateral prominent margins of two 
contiguous series uniting, a dividing ridge or keel is formed, 
which, when viewed transversely, gives to the cross section of 
the stem a slightly multiangular appearance. The cell-depres- 
sions lead upwards and inwards to the true cell-aperture or 
orifice, considerably smaller than the larger opening, and ap- 
parently oval in outline. 
The cells are at first vertical, and then curve obliquely up- 
wards and outwards to the surface, where they open at right 
angles to the imaginary axis, the pyriform depression in which 
* vacua, tissue or web; mopos, a passage or pore. {The specimens are 
in the collection of the Geological Survey of Scotland; and this descrip- 
tion is published by permission of the Director-General of the Geological 
Survey. | 
