SPECIES OF CLADOPHOEA. 



175 



and irregularly branching and rebranching. Ease unknown. Calycles 

 monopiionidian ?, often with, long acute denticles, which have an 

 ascending direction. 



We have only one fair example of this genus from the Mid-Wales 

 beds ; and the foregoing characters are all that can be made out. 

 The height of the visible portion of the polypary is less than half an 

 inch. The main branches are apparently about one fortieth of an inch, 

 in diameter below, and are strongly striated throughout the whole of 

 their extent. The right-hand branch, which, is the better preserved, 

 throws off three secondary branches in the upper half of its length. 

 These secondary branches are of various lengths, being so extended 

 that their outer terminations are on, or about, the same level. Each, 

 secondary branch splits at its summit into two secondary branchlets 

 or polypiferous spines, about one twentieth of an inch in length, 

 and terminating outwards in a short, stiff, mucronate point. The 

 remaining primary branches present essentially the same general 

 features. 



One margin of the branches exhibits small denticulations at short 

 and regular intervals (about 50 to the inch), marking the mouths 

 of the calycles, the margins of which are usually concave. The 

 outer angle of the aperture is sometimes very slightly projecting and 

 more or less rounded off, as in the genus Dictyonema. Generally, 

 however, the outer margin of the aperture is prolonged into a stout 

 denticle, which stretches outward and upward at an angle of about 

 45 degrees to the main axis of the branch, and is terminated in 

 a blunt point; the inner margin of the calycle, shown by a little 

 groove upon the surface of the branch, running for some distance 

 almost parallel with the outer margin. 



The colour of the test is black, and the texture corneous. 



Horizon and Locality. Llandovery of the Devil's Bridge, Aberyst- 

 wyth. 



Odo^tocatjlis, gen. nov. 



Gen. char. Polypary cyathiform, composed of numerous indepen- 

 dent and frequently bifurcating polypiferous branches, originating 

 from the distal extremity of a short stem, which is likewise poly- 

 piferous, and is terminated proximally in an irregular corneous 

 expansion. Hydrothecss of the type of those of Dictyonema, 

 biserial, subalternate. 



The chief peculiarity of this genus is afforded by the character of 

 the stem, which is identical in every respect with the main branches, 

 and, like them, is denticulate or polypiferous throughout the whole of 

 its extent. It commences proximally in a flattened expansion, with 

 irregular or frayed-out edges, possibly the remains of a disk or bulb 

 of attachment. 



The mode of branching is rigidly dichotomous, the first two 

 branches being formed by the subdivision of the main stem itself. 

 Each arm branches and rebranches again and again in the same 

 manner, at frequent and close intervals, composing an elegant cyathi- 

 form or fanlike polypary, very symmetrical in form. The branches 

 retain their original width to their final division, which gives rise to 

 two minute branches less than one tenth of an inch in length. 



