RENIERA. 141 



transverse section, tapering evenly but somewhat abruptly, from the central disc 

 to an obtuse termination. The rays forming the vertical axis, when complete, 

 appear to be as long as the horizontal rays. There is considerable variation in 

 the dimensions of the spicules ; the individual rays, measured from the centre of the 

 disc, vary from V2 mm. to 3*2 mm. in length and from *3 to *6 mm. in thickness 

 at their bases. 



The spicules of this species are characterised by the tapering conical form of 

 the rays, and by the development of the rays of the vertical axis. In this latter 

 feature they agree with spicules described by Prof. Schliiter from Devonian Rocks 

 of the Bifel, under the name of Octacium rhenanum ; x but, judging from the figures 

 and measurements given by Prof. Schliiter, the rays in our species, besides being 

 larger, taper more abruptly. In Astrceospongia meniscoides, 2 Dewalque, also from 

 the Eifel, the spicules are larger than those of the present species, the rays are 

 fusiform rather than conical, and no mention is made of the presence of vertical 

 rays. In A. Hamiltonensis, Meek and Worthen, 3 from the Devonian of North 

 America, the spicules are smaller, and do not appear to possess vertical rays. 



The forms described and figured were discovered by Mr. J. Smith, of Kilwin- 

 ning, in decayed limestones. They are now of crystalline calcite, their surfaces are 

 much eroded, and in some instances partially obscured by matrix. 



Distribution. — Middle Devonian : Newton Abbott, Devonshire. 



CARBONIFEROUS SPONGES. 



Sub-Order. — MoNACTiNELLiDiB. 



Genus. — Rbnieea, 0. Schmidt. 



1870. Die Spongien des adriatischen Meeres, p. 72. 



Syn. — Rayneria, Nardo ; Pellina, 0. Schmidt; Prianos, Gray. 



Sponges of variable form. The skeleton consists of acerate and cylindrical 

 spicules, which are disposed so as to form a polygonal meshwork ; the spicules 

 held together at their ends by spongin. 



The connected skeletons of Sponges of this genus are unknown in the fossil 



1 ' Sitzungsb. der niederrbein. Gesellsch. Bonn,' p. 151 ; ' Zeitschrift; d. deutscben geolog. Gesell- 

 Bchaft,' 1887, p. 23, Taf. ii, figs. 7—9. 



2 ' Bull, del' Acad. Koy. de Belgique,' vol. xxxiv, 1872, p. 24, pi. xxvi. 

 8 ' Geol. Surv. Illinois,' vol. iii, p. 419, pi. x, fig. 6. 



T 



