214 DEVONIAN FAUNA, 



II. Firm Hi/ — CodonasteridzE, Etheridge and Carpenter, 1886. 

 1. Genus — Oodonaster, M'Coy, 1849. 

 1. Codonaster conicus, ii. sp. Plate XXIX, figs. 4, 4 a. 



Description. — Calix very elongate, subfusiform. Base apparently trilobate. 

 Summit very gently convex. Radial plates nearly half as long again as the basal, 

 and separated from them by a slightly zigzag suture. Section of upper parts of 

 the calix distinctly pentagonal, apparently becoming slightly stellate at the 

 summit. Upper margins of the interradial sinus forming a very low triangle. 

 (Shape of deltoid plates unobserved.) Ambulacra apparently moderately narrow, 

 short, curving gently downwards near their distal ends. Deltoid plates apparently 

 bearing a strong ridge along their centre. Anus semicircular, situated very near 

 the centre ? Hydrospire-slits few and coarse. 



Size. — Length about 6 mm., width about 3 mm. 



Locality. — A single specimen (with part of its mould) from Top Orchard 

 Quarry is in the Woodwardian Museum. 



Remarks. — This little specimen is crushed, and being in the state of preserva- 

 tion usual in these beds its details are indistinct. This is especially the case at 

 its summit, where not only is it squeezed together but its surface has been mostly 

 carried away with the mould. From its general shape, however, and what 

 indications of its structure remain, there seems no reason for doubt that it 

 belongs to the genus Codonaster. The spaces in the ambulacra seem very few and 

 coarse, indications of three or four of them being seen. Three or four ridges 

 (more or less parallel) outside some of the ambulacra, where the surface is broken 

 away, appear to be the upper part of the hydrospire-slits. Remains are seen of a 

 circular or semicircular wall round the central area, and there is a round pit, which 

 may be the anus. The upper margins of the interradial sinuses are defective, 

 but they appear to have been elevated into low triangles and probably to have 

 been bent obliquely inward at the summit. Five short coarse radii, dividing the 

 interradial areas on the summit, appear to be the ridges on the deltoid plates. 



Affinities. — From the Carboniferous C. trilobatus, M'Coy 1 (which, including 

 C. acvtus, M'Coy, 1 is the only described English species), our Pilton form is totally 

 different in shape ; but to the Upper Devonian C. Hindi i, Etheridge and Carpenter, 2 



1 1849, M'Coy, ' Ann. Mag. Nat. Hist.,' vol. iii, p. 251. 



2 188(5, Etheridge and Carpenter, ' Catal. Blastoid. Brit. Mus>.,' pp. passim, pi. xii, figs. 4 — 7. 



