150 BRITISH PALEOZOIC SPONGES. 



30. Geodites antiquus, Hinde. Plate V, figs. 3, 3 a — 3 d. 



1883. Geodia? antiqtja, Hinde. Cat. Foss. Sponges, p. 208, pi. xxxviii, figs. 5, 



5 a — 5 e. 



Detached bifid and trifid zone-spicules, with elongated, cylindrical, or sub- 

 cylindrical shafts, and simple, short, obtusely-pointed head-rays, projecting 

 obliquely forwards at angles between 45° and 52°. The shafts in all the spicules 

 are incomplete, the longest fragment measures 2 mm.; they vary from '15 to '25 

 mm. in thickness. The spicular head-rays are about *35 mm. in length. Detached 

 acerate spicules occur in the same beds with the trifid spicules, and also in other 

 beds in which no trifid forms have as yet been found. These acerates are fusiform, 

 straight, or slightly curved, smooth, and pointed. Provisionally they may be 

 regarded as belonging to the same species as the trifid forms. They vary from 

 2 mm. to 3*9 mm. in length and from "1 to '22 mm. in thickness. 



Distribution. — Yoredale series : Harrogate, Richmond, Arkendale, Yorkshire ; 

 Halkin, Trelogan, Flintshire. Carboniferous Limestone : Clitheroe, Lancashire. 

 Lower Limestone series ; Low Baidland (J. Smith); Law Quarry, Dairy (J. Bennie). 

 Upper Limestone series, Glencart, Dairy (J. R. S. Hunter, J. Smith). 



31. Geodites defoemis, Hinde, sp. nov. Plate V, figs. 4, 4 a — 4g. 



This species includes very robust bifid and trifid zone-spicules, their shafts are 

 straight or slightly curved, thickest near the summits, where they are slightly 

 compressed ; below the summits the shafts are circular in transverse sections. In 

 several specimens the head of the shaft extends slightly beyond the point from 

 whence the head-rays are given off (Plate V, 4/), and there is usually a small 

 central depression at the top of it. The spicular rays are relatively short, stout, 

 conical, and obtusely pointed ; they project obliquely forwards at angles varying 

 between 45° and 70°. In the bifid spicules the head of the shaft is usually com- 

 pressed and the rays are opposite to each other. The rays in the same spicule are 

 apparently inequal in length; they range from *7 to 1*4 mm. in length by '4 mm. 

 in thickness near their bases. The shafts in all the specimens yet discovered are 

 broken and incomplete ; they vary in thickness from "6 to 1*05 mm. 



Accompanying the bifid and trifid spicules are unusually robust, slightly 

 curved, sub-cylindrical or fusiform spicules, with apparently rounded extremities, 



