144. BRITISH PALASOZOIC SPONGES. 
23. Reniera Graciuis, Hinde. Plate IX, figs. 7, 7 a, b. 
1885. Rentera Gracinis, Hinde. Beds of Sponge-Remains in Lower and Upper 
Greensand, Phil. Trans., p. 436, pl. xh, 
figs. 1, 1 4. 
Cylindrical spicules, gently arcuate, smooth, with evenly rounded ends. Average 
length ‘4 mm., thickness ‘05 mm. These spicules correspond closely with those 
described under the above name from the Lower and Upper Greensand of Surrey 
and Devonshire. They are distinctly shorter than the spicules of R. virgata. 
Distribution.—Yoredale series: Richmond, Yorkshire. 
24, Rentera Zirrent, Pocta. Plate IX, figs. 8, 8a—8c. 
1884. Rentera Zrrrert, Potta. Sitzungsber. der kénigl. béhm. Gesellsch. der 
Wiss., vol. 1884 (1885), p. 8, pl. i, figs. LO—14. 
1885. — — Hinde. Phil. Trans., p. 437, pl. xli, figs. 4—4e. 
Acerate spicules, straight or gently arcuate, smooth, either fusiform and gently 
tapering to both ends, or nearly even throughout and somewhat abruptly pointed. 
Length from *3 to *5 mm. and from ‘03 to ‘04 mm. in thickness. 
These Carboniferous spicules cannot be distinguished from the forms occurring 
in the Greensands of Surrey and Devonshire, and in the Cretaceous strata of 
Bohemia and Westphalia. 
Distribution —Yoredale series: Richmond, Yorkshire; Halkin, Henblas, near 
Holywell, North Wales. Carboniferous Limestone : Clitheroe. Upper Limestone 
series : Benachlan, Ben Bulben, Sligo. 
25. Renrera BActLLUM, Hinde, sp. nov. Plate IX, fig. 9. 
Very slender cylindrical spicules, either gently curved throughout their length, 
or somewhat abruptly incurved near one or both ends. Their surfaces are smooth, 
and their extremities evenly rounded. They vary from ‘23 mm. to*5 mm. in length, 
and ‘02 mm. in thickness. These forms are readily distinguishable from those 
previously described by their slender proportions. They are extremely abundant 
in some of the cherty Sponge-beds, which are mainly composed of their minute 
