60 SILICEOUS SPONGES. 



Phtmatella nodosa, Hinde, n. sp. (Plate XI. figs. 2, 2 a.) 



Sponge nearly cylindrical or tapering in form, the basal end rounded and destitute 

 of any peduncle or point of attachment ; the summit of the specimen has not been 

 preserved. The surface in the upper portion is covered with obtusely rounded nodes ; 

 the lower portion is nearly smooth. The single imperfect example is 165 mm. in 

 lensth, GO mm. wide at the summit, and 40 mm. at the base. The wall is 20 mm. in 

 thickness at the summit. 



The cloacal tube extends for a distance of three fourths the length ; it is 21 mm. 

 wide at the top, and 10 mm. at the lower end. The canals opening into the cloaca 

 are 1-2 mm. wide, and they have a downward curve. The exterior surface of the 

 sponge exhibits apertures of various sizes, which appear to be the openings of canals 

 which extend in a curved direction towards the interior of the wall. 



The spicular structure of the interior has been obliterated, but on the outer 

 surface in some places small tetracladine spicules can be seen ; the arms are smooth, 

 about -2 mm. in length ; the nodes at the junction of the arms are inconspicuous. 



In outer form this species somewhat resembles Phymatella Jieteroinorjiha*, B-cemer, 

 sp., but the walls are much thicker and the canal-apertures smaller than in that 

 species. In the curved direction of the canals this species differs from the typical 

 forms of the genus, but in other respects its characters are similar. 



Distribution. Upper Green Sand : Warminster. 



* 



Phtmatella, sp. 



Distribution. Upper Chalk : South of England ; France 1 



Genus AULAXINIA, Zittel, 1878. 



^ AuLAxiNiA SULCIFEKA, Roemer, sp. 



Siphonocoelia sulcifera, F. A. Roemer, Palseont. Bd. 13, p. 30, t. 11. f. 7. 

 Aulaxinia sulcifera, Zitt. Studien, II Ab. p. 75, t. 8. f. 4. 



Distribution. Upper Chalk ■? 



Aulaxinia costata, Hinde, n. sp. (Plate XII. figs. 1, 1 a.) 

 Sponge elongated, inversely conical, with rounded summit (no stem preserved); 

 length 80 mm. by 35 mm. in width. The cloacal aperture is 9 mm. in width ; from 

 its margin a series of eighteen nearly straight simple canals, 2*3 mm. in width, and 

 equidistant from each other, extends to the base. Between these vertical canals are 

 the apertures (about 1 mm. in width) of the horizontal canals. The spicules are 

 relatively large, the arms apparently smooth and about -5 mm, in length. 



• Palsontographica, Bd. 13, p. 22, t. 8. f. 11. 



