70 SILICEOUS SPONGES. 



Hallirhoa hrevicostata, which they do not at all resemble. On the other hand, this 

 same author has given the name of Siphonia acauUs to an example of this species 

 from Cap la Heve. Examples from this locality in the Museum collection distinctly 

 show the resemblance to specimens from Warminster, in spite of the different aspect 

 resulting from fossilization. This species has also been referred to Hippalimus 

 funqoides, Lamx. ; but though I have not seen an example of this form, the descrip- 

 tion and figure of Lamouroux represent an altogether different sponge from the 

 present species. 



Distribution. Upper Green Sand : Warminster ; Ventnor, Isle of Wight ; Cap la 

 Heve, Seine-Inferieure. 



Genus JEREA, Lamouroux, 1821. , 



JeREA PTKIFOEillS, Laiiix. 



1821. Jerea 2iyriform.'is, Lamx. Exp. method, p. 79, t. 78. f. 3. 

 1847. Jerea pyriformis , Mich. Icon. Zooph. p. 133, t. 36. f. 3. 

 1878. Jerea pyriformis, Zitt. Studien, II Ab. p. 81. 



Distribution. Craie Chloritee : Vaches Noires, Havi-e. 



Jerea Websteri, Sowerby, sp., MS.1 



1814. Tulip Alcyonium, Webster, Trans. Geo). Soc. vol. ii. p. 377, t. 28. 

 1854. Siphonia Websteri, Morris, Cat. Brit. Foss. p. 30. 



Sponges pear-shaped or ovate in form, with a conical summit, and gradually 

 tapering to a somewhat slender stem at the base. In none of the Museum 

 specimens has the stem been preserved ; but according to Webster's figures it 

 appears to have been unusually long. The body of a small individual is 48 mm. 

 in length by 20 mm. in width, whilst a large specimen measures 81 mm. by 51 mm. 



x\t the summit is a closely arranged group of canal-apertures 1"5 mm. each in 

 width, which open directly at the surface and not in any depression. Down the 

 sides are shown in some specimens longitudinal, sinuous, branching canals. The 

 spicular structure is not clearly exposed. 



Prof. Morris quotes Sowerby as the author of this species, but I have not been able 

 to discover the published description. 



Distribution. Upper Green Sand : Warminster ; Isle of Wight. 



Jerea reticulata, Hinde, n. sp. (Plate XV. figs. 2, 2 «, 2 b.) 



Sponges fig-shaped or subspherical, with slightly truncated summits, either with 

 a short peduncular stem or apparently sessile. A small specimen is 26 mm. in height 

 by 21 mm. in width, whilst a fairly large globular form is 35 mm. in height by 42 mm. 

 in width. 



