48 BRITISH PALAZOZOIC FOSSILS. [ Potyzoa. 
3rd Family. MYRIAPORID. 
Corallum always strongly fixed at base by a root-like calcareous expansion (distinguishing them from 
the Escharide) ; cells short, oval, never prolonged into tubes (separating them from the Zwhuliporide). 
Genera :—1, Retepora; 2, Glauconome ; 3, Fenestella ; 4, Synocladia, &e. 
Genus. RETEPORA (Lam. restricted by Blain.) 
= Elasmopora (King). 
Gen. Char.—Corallum forming a fan-shaped, or irregularly cup-shaped, expanded net-work, composed of 
frequently anastomosing interstices, leaving subregular, ovate quincuncially arranged fenestrules; upper or 
inner surface closely set with several rows of small, close, uniformly-arranged, oval cell-mouths (on the 
dissepiments as well as on the interstices), the cells oblique to the surface; outer surface with dense, 
minutely granulose striz. 
The absence of distinct nonporiferous dissepiments separates this from Polypora (M°Coy), the same 
character and the numerous rows of cells separate it from /enestella, as well as (according to Lonsdale) the 
want of a layer of vertical tubuli to the nonporiferous face. 
Retepora Histnceri (M/'Coy). Pl. 1. C. fig. 18. 
Ref—M°Coy, Ann. Nat. Hist. 2nd Series, Vol. VI. 
Sp. Ch.—Corallum forming irregular fan-shaped expansions ; interstices about one-third of a line wide ; 
dissepiments narrower than the interstices; fenestrules ovate, slightly angulated about two-thirds of a line 
long and half a line wide (five interstices in the space of two lines), cells very small, from four to seven 
rows on the interstices, generally about three on the dissepiments, internally forming short ovate cells about 
a third longer than wide; obverse very minutely granular. 
As it is scarcely possible ever to determine Hisinger’s Retepora reticulata with certainty, (as he gives 
no information relative to the pores), there could be no objection to applying that name to the present 
species, which agrees with his figure as far as it goes, were it not that Mr Lonsdale has already applied 
it to a very similar coral, which he however places in the genus /enestella, and figures with only the two 
rows of pores usual in that genus. 
Position and Locality—Very abundant in the slates of Cefn Coedog ; Cyrn y Brain, W. of Wrexham, 
Denbighshire; Blain y Cwm, W. of Nantyre, Glyn Ceiriog, Denbighshire ; slates of Mynydd, Fron Frys, 
five miles W. of Chirk, Glyn Ceiriog; and in the Coniston limestone of Coniston Water-Head, Lancashire. 
Explanation of Figures—PI. 1. C. fig. 18. Natural size from Coniston limestone, of Coniston Water- 
Head.—Fig. 18a. Cast of portion of ditto, magnified seven diameters, shewing the casts of the numerous 
cells left by the decomposing corals. ‘ 
> 
Genus. GLAUCONOME (Gold. as restricted by Lonsd.) 
= Penniretepora (D’Orb.) Prod. = Acanthocladia (King). 
Gen. Char.—Corallum of a narrow central stem, with numerous pinnules or lateral branches unconnected 
with each other; both stems and branches have two rows of cells on one face which is usually carinated 
between them; in some species a row of small cells on the keel; opposite face striated. 
In decomposing specimens the cells are seen to be short, ovate, or pyriform vesicles, arranged in rows 
obliquely under their external openings on the surface. As Mr Lonsdale has very properly restricted 
Goldfuss’s generic name to the present corals, restoring Goldfuss’s simple species to Vincularia (Defr.) 
I do not see the necessity for the new names more recently proposed. 
