INOBOLIA.— STELLISPONGIA. 185 



irregular interspaces between the fibres. The fibres are mainly composed of rela- 

 tively large three- and four-rayed spicules, the rays of which are disposed in the axis 

 of the fibre. The dermal layer is composed of minute, apparently three-rayed 

 spicules. 



In its spicular structure this genus is allied to Lymnorea and some species of 

 Peroiiella ; but its mode of growth and the absence of canals readily distinguish it 

 from both of these genera. 



Inobolia inclusa, Ilinde, n. sp. (Plate XXXV. figs. 2, 2 a, 2 b.) 



The examples of this species are from 20 to 42 mm. in height, and from 27 to 

 50 mm. in width. The fibres, as seen in a vertical transparent section, vary from 

 T5 to -2 mm. in width ; they anastomose so as to form a very irregular mesh. Their 

 condition is largely crystalline, so that only the rays of the large axial spicules can 

 be distinguished. A single ray of one of these measured -24 mm. in length by "OSG 

 in width. In one place the dermal layer, examined by a strong lens, shows numerous 

 minute three-rayed spicules, the rays of which closely intercross each other. 



Whilst in the best-preserved examples no traces of canals are to be seen, there 

 are some specimens which show here and there the apertures of tubes resembling 

 those of Ocidosjwngia. These tubes, however, have no regular course in the substance 

 of the sponge, and appear to me to result from extraneous sources. The spicular 

 structure of specimens possessing the tubes is similar to that of typical examples of 

 the species. This species is apparently abundant. 



Distribution. Inferior Oolite. (Pea Grit) near Cheltenham. 



Genus STELLISPONGIA, D'Orbigmj, 1847. 

 Stellispongia eotulakis, Milnst. sp. 



1841. Cnemidium rotulare, Miinst, Beitr. zur Petref. iv. p. 31, t. 1. f. 25. 



1841. Cnemidium Manon, Miinst. ib. p. 30, t. 1. f. 20. 



1841. Cnemidium astroites, Miinst. ib. p. 31, t. 1. f. 24. 



1864. Stellispongia Manon, Laube, Deaks. d. k. Akad. d. Wiss. Bd. 24, p. 238, t. 1, 



f . 15 a, b, c. 



1878. Cnemidium rotulare, Qucnst. Petref. Bd. 5, p. 527. 



1878. Stellispongia rotularis, Zitt. Studien, III Ab. p. 40. 



Distribution. Trias : St. Cassian, Tyrol {coll. Klipstein). 



Stellispongia variabilis, Miinst. sp. 



1841. Cnemidium variabile, Miinst. Beitr. zur Petref. iv. p. 30, t. 1. f. 21-33. 

 1841. Cnemidium turbinatum, ]\Iiiust. ib. p. 30, t. 1. f. 19. 



1843. Cnemidium stellare, Klipst. Beitr. z. g. Kennt. d. ost. Alpen, p. 291, t. 20. f. 6. 



2b 



