140 BRITISH PALEOZOIC SPONGES. 



plates, and overlap the rays of adjoining spicules. The ray pointing to the outer 

 margin of the Sponge not infrequently projects over the spicular plate in advance 

 of it. The entering or vertical ray of the spicule is usually contracted immediately 

 beneath its junction with the transverse rays, it then expands and is nearly evenly 

 cylindrical to its junction with the plate of the inner wall. The characters of the 

 plates forming the inner or upper wall in this species have not clearly been made 

 out. They appear to be sub-quadrate in form, and in close contact with each 

 other. It is doubtful whether there were perforations at the angles of the plates, 

 as is clearly the case in B. occidentalis, Salter, and in a specimen from the 

 Devonian of Canada, which, in all other respects, resembles the European forms 

 of this species. 



The only undoubted example of this species from British strata is a frag- 

 mentary individual discovered by the late A. Champernowne, Esq., F.G.S., showing 

 an impression in hardened mudstone of a portion of the inner surface of the wall 

 and transverse sections of the vertical spicular rays (PL IV, fig. 1). Fragmentary 

 specimens likewise occur in Wenlock strata at Malvern, which may provisionally 

 be referred to this species, though the characters preserved are insufficient for 

 satisfactory determination. They consist of impressions of the under or outer 

 surface of the wall of flattened specimens of at least ] 20 mm. in diameter, showing 

 the lozenge-shaped depressions formed by the casts of the spicular plates and 

 traces of the transverse rays beneath them (PI. II, fig. 3). In none of the 

 specimens is the structure clearly shown, and the principal grounds for referring 

 them to B. Neptuni are the correspondence in the form and dimensions and in the 

 crenulated margins of these outer plates to those of typical forms of this species 

 as figured by Giimbel. 1 



Distribution. — Silurian : Wenlock strata, Malvern. Middle Devonian : Mud- 

 stone Bay, Devonshire. Also in Devonian strata at Ohimay, Couvin, and other 

 localities in Belgium, Ober-Kunzendorf, Silesia ; Eifel, Germany ; near Widder, 

 Ontario, Canada. 



Sub- Order. — Octaotinellioe. 



18. Astr^eospongia Dbvoniensis, Hinde, sp. nov. Plate IV, figs. 8 a — 8 c. 



The form of the Sponge unknown ; the species is based on detached spicules 

 in which both the rays of the vertical axis are developed, as well as the six hori- 

 zontal rays. The rays are robust, conical, circular, or slightly compressed in 

 1 ' Beitrage Abhandl. d. k. bay. Akad. der Wiss.,' 01. ii, Bd. xii, pi. a, figs. 3 a, 4 a. 



