232 BRITISH JURASSIC SPONGES. 
placed under this genus. The specimens are not uncommon in the Inferior Oolite, 
but as yet only one has been met with in the Great Oolite. 
Distribution.—Inferior Oolite. Parkinsoni-zone at Shipton Gorge, near 
Bridport (Coll. Mr. E. A. Walford). Great Oolite, Hampton Down, near Bath 
(Coll. Rev. G. F. Whidborne). Also in the Lias near Balingen, Germany 
(Quenstedt). 
40. Honcosroncia BELLA, Hinde, sp. nov. Plate XVII, figs. 6—6 e. 
Sponges small, simple, discoidal, circular in outline, the basal surface either 
flattened where it has grown on an even surface, or convex with a slight pedicle, 
and enclosed in a corrugated dermal layer which forms a shallow saucer extending 
as high as the wall. The upper surface is flattened or slightly raised in the centre, 
with several well-marked, straight, open grooves, from *3 mm. to ‘5 mm. in width, 
radiating from the centre or between this and the margin. Between the 
erooves are slightly raised ridges, on each of which is a row of circular or ovate 
canal apertures from -3 mm. to ‘5 mm. wide. The skeletal fibres are openly 
arranged ; they vary from*075 mm. to ‘12 mm. in thickness. The fibres show the 
spicular structure very indistinctly ; they are chiefly made up of three-rayed 
spicules surrounded by smaller filiform spicules. 
The specimens are only from 4 mm. to 9 mm. in breadth, and from 1 mm. to 
3°5 mm. in thickness. They are now mostly free, but they appear to have grown 
attached to other organisms; one specimen still remains firmly fixed to a fragment 
of a Hexactinellid sponge. From H. liasica the species is principally dis- 
tinguished by the regular arrangement of the surface grooves and the canal 
apertures. 
Distribution.—Inferior Oolite. Parkinsoni-zone at Shipton Gorge. (Coll. 
Mr. E. A. Walford.) 
41. Hoxocosponeta mitrATA, Hinde, sp. nov. Plate XVII, figs. 7—7 d. 
Sponges small, usually simple, but occasionally two are attached together by 
the dermal layer, depressed conical to subcylindrical, base flattened, covered by a 
rugose dermal layer, summit conical or rounded, with from three to five deep open 
grooves from *6 mm. to 1 mm. in width, which radiate from the centre and extend 
down the sides. At the centre in some specimens there is a single oscule, but in 
