SYNOPELLA.— OCTJLOSPONGIA. 191 



species, are small, hemispherical, or amorphous masses, from 28 to 42 mm. in width 

 and about 26 mm. in height, frequently with a concave base, enveloped in a compact, 

 concentrically wrinkled dermal layer ; the rounded upper surface is either smooth or 

 with slight elevations, on which several small canal-apertures are grouped together. 

 The interspaces between the canal-openings only exhibit irregular pores between the 

 fibres. The fibres are from -15 to -3 mm. in width. I have not been able to ascertain 

 the spicular structure. 



The Farringdon examples are smaller than the specimen figured by Goldfuss from 

 Essen, but in other respects they appear to correspond. The forms from the 

 Maestricht Chalk, also referred by Goldfuss to the same, appear to me to belong to 

 a different species; and as Zittel has applied Goldfuss's name to the Essen forms, I 

 propose to adopt another designation for those from Maestricht. 



Distribution. Lower Green Sand : Farringdon, Berkshire. 



Synopella sph^rica, Mich. sp. 



1840-47. Lymnorea spheerica, Mich. Icon. Zooph. p. 216, t. 52. f. 16 a, b. 

 1878. Synopella sphoerica, Zitt. Studien, III Ab. p. 43. 



Distribution. Cenomanian : Essen an der Ruhe. 



Synopella Goldpussi, Hinde, n. sp. (Plate XXXVI. fig. 2.) 



1826-33. Manon imlvinarium, Goldf. pars, Petref. 1 Th. p. 2, t. 1. i. Q a, b (non t. 29. 

 f. 7 a, b). 



Sponges inversely conical, subcylindrical, flattened, cake-shaped, or laterally com- 

 pressed, from 8 to 20 mm. in height and from 10 to 19 in width. The base and 

 sides are invested in a compact, concentrically wrinkled dermal layer ; the truncate or 

 rounded upper surface has from one to three small groups of canal-apertures, from 

 which several deeply marked open furrows radiate ; beyond these the surface exhibits 

 irregular apertures between the fibres. Minute structure unknown. 



The radiating canals on the summit, which readily distinguish this from the two 

 preceding species, also give it the appearance of Stellispongia, and one can with 

 difficulty decide whether it should be ranged under that or the present genus. 



Distribution. Upper Chalk : Maestricht. 



Genus OCULOSPONGIA, From. 1859. 



Ocdlospongia binoculata, Quenst. sp. 



1878. Spongites binoculatus, Quenst. Petref. Bd. 5, p. 248, t. 126. f. 59. 

 1878. Oculospongia binoculata, Zitt. Studien, III Ab. p. 43. 



Distribution. Upper Jura : Giengen, Nattheim, Wiirtemberg. 



