76 SILICEOUS SPONGES. 



Genus CALYMMATINA, Zittel, 1878. 



Caltmmatina eimosa, Zittel. 

 1878. Calymmatina rimosa, Zittel, Studien, II Ab. p. 85, t. 2. f. 2, and t. 9. f. 8. 



There is a single specimen in the Collection which, so far as can be determined 

 from its imperfect preservation, appears to belong to the above species. Nothing is 

 known as to the locality whence it comes ; judging from the matrix it would seem 

 to have been derived from the Upper Chalk. 



Genus TUEONIA, Iliclielin, 1847. 



TuEONiA VARIABILIS, Michclin. (Plate XVIII. fig. 1.) 



1847. Turonia variabilis, Mich. Icon. Zoopli. p. 126, t. 35. f. 1-8. 



1861. Turonia variabilis et sulcata, Court. Epouges foss. p. 25, t. 40. f. 1-3. 



1878. Turonia variabilis, Zittel, Studien, II Ab. p. 86. 



Sponges conical in form, with a flattened or rounded base, from which one or more 

 radical processes project. A small example is 21 mm. in height by 25 mm. in width ; 

 another specimen is 52 mm. in height by 42 mm. in width. 



The upper, distinctly conical portion of the sponge has a tubular cloaca, which 

 opens at the summit of the cone; the sides are rough and deeply furrowed with 

 open canals, which radiate downwards from the edge of the cloaca ; in these canals 

 are occasionally seen the apertures of smaller canals, which penetrate to the interior 

 of the sponge. The lower margin of the upper cone overlaps slightly the upper 

 portion of the base, and is usually distinctly marked off from it by a well-defined 

 furrow. The basal portion is smooth and compact. 



The mesh-spicules have robust arms and branching extremities. The dermal layer 

 is partly composed of very minute irregular-shaped spicules, and partly of minute 

 trifid spicules with delicate horizontally expanded head-rays. 



This species is rare in this country. I have only seen two imperfect examples ; it 

 appears to be abundant in the neighbourhood of Tours. The specimen figured is 

 probably from France ; the particular locality is unknown. 



Distribution. Upper Chalk : Flamborough, Yorkshire ; South of England ; France. 



Genus KALPINELLA, Hinde, n. g. 



Sponges simple, cup- or vase-shaped, supported on a cylindrical or compressed 

 stem, with root-like processes at its termination. Margins rounded. Both the 

 interior and exterior surfaces of the sponge-wall with numerous canal-apertures. 

 The canals are somewhat sinuous and extend through the wall at right angles or 

 obliquely to the surface. Vertical canals also extend down the stem. 



