PEKONELLA. 167 



In a longitudinal section of a specimen, the fibres near the outer portion of the 

 stem appear as closely reticulate bands, about •! mm. in width, whilst in the inner 

 portion they are more open and slender, and seem to be mainly composed of single 

 axial rays of three- or four-rayed spicules. Similar spicules are also present in the 

 axial line of the wider marginal fibres, but the other spicules of the fibre have been 

 obliterated. The spicular rays are from -1 to '2 mm. in length. 



The delicate character and the spicular arrangement of the fibres distinguish this 

 species from P. pistilliformis, with which it agrees in the form and size of the 

 individual spongites. Though resembling P. mamillifera in the spicular characters 

 of the fibres, it is a distinctly smaller form. 



Distribution. Inferior Oolite (Pea-Grit) : near Cheltenham. Couche a Polypiers : 

 Eanville (coll. Tesson). 



Peronella inflata, Hinde, n. sp. (Plate XXXII. figs. 6, 6 a, 6 b.) 



Sponge forming a bushy mass of upright stems or branches. The only specimen 

 is 100 mm. in height, and about the same in its greatest width. The stems are sub- 

 cylindrical, with occasional inflations and contractions, and also nodose swellings ; 

 they vary from 10 to 20 mm. in thickness. At the summit of each stem is a minute 

 chimney-like extension, from 3-5 to 7 mm. in width, penetrated by a circular cloacal 

 aperture about 3 mm. in diameter. The outer surface of the sponge shows closely 

 arranged vermiculate fibres, with small irregular interspaces. 



In a transparent transverse section of one of the stems there is shown a marginal 

 ring, about 3 mm. in width, of very closely arranged delicate fibres about -1 mm. in 

 thickness. These fibres are formed of three- or four-rayed spicules, of relatively 

 large size, a single ray measuring -25 to -3 mm. in length, and from "04 to -05 mm. in 

 thickness. The spicular rays are usually arranged in the direction of the fibre. The 

 central portion of the stem, within the marginal ring, is filled with an open reticulate 

 fibre, which appears to be mainly composed of similar spicules to those of the marginal 

 portion, but arranged in a single series, so that the ends of the rays of adjoining 

 spicules only slightly overlap each other. 



The spicular structure of this species is of the same character as in the two 

 preceding forms, P. tenuis and P. mamillifera ; but it is readily distinguished from 

 these by the larger size and diff'erent form of the component stems. 



Distribution. Middle Jura : Couche a Polypiers — Eanville, near Caen, 



Peronella cylindeica, Goldf. sp. (Plate XXXIII. fig. 4.) 



1826-33. Sajphia cylindrica, Goldf. Petref. 1 Th. p. 5, t. 2. f. 3, and t. 3. f. 12. 



1826-33. Scyphia elegans, Goldf. Petref. 1 Th. p. 5, t. 2. f. 5, 13. 



1848. Scyphia cylindrica, M'Coy, Ann. & Mag. Nat. Hist. 2iid ser. vol. ii. p. 418. 



