JEEEICA. — CCELOCOEYPHA. > 43 



narrow cylindrical base ; occasionally slight constrictions are present. The largest 

 example in the collection is 140 mm. in length and 48 mm. in diameter. 



At the summit is a group of closely arranged circular or polygonal openings of 

 vertical canals, each 2 '8 mm. wide. The lateral surface of the sponge appears to 

 have been smooth, and thickly covered with minute pore-like apertures 0'3 mm. in 

 width. Beneath the dermal layer very delicate anastomosing fibres can be seen, 

 which are apparently composed of minute thorny spicules ; but the forms of these 

 spicules are not sufficiently clear to be figured. 



The S. ocellata, F. A. Eojm., appears to be identical with this species. Eoemer 

 states that only six canal-apertui'es are present on the summit of his sponge ; but the 

 number of these canals evidently depends upon the size of the individual specimen, 

 and furnishes no ground for a specific character. 



Disiribufion. Upper Chalk : Flamborough. 



Jeeeica ctlindrica, Hinde, n. sp. (Plate VI, figs. 1, 1 a.) 



Sponge massive, compressed, cylindrical, with an expanded flattened base ; the 

 summit truncate, with a shallow basin-like depression. The only specimen is 72 mm. 

 in height and 84 mm. in width. 



The surface characters are not well preserved, as the dermal layer has disappeared, 

 and only filled up sinuous canals running in a vertical direction can be distinguished. 

 In a vertical section through the central portion of the sponge, however, there are 

 exposed two sets of canals — one generally vertical, and the other extending from the 

 lateral surface to the central portion of the sponge. Both series of canals are minute, 

 and do not appear to exceed O'o mm. in width. 



The spicules of this sponge are very irregular in form, with numerous thorny 

 and tubercular branches. They appear to be loosely connected together by their 

 twig-like extensions ; and distinct spicular fibres are not apparent in the vertical 

 section. 



In its general form and size, as well as in the delicate character and disposition of 

 the canals and spicules, this species may be readily distinguished from the others of 

 this genus. 



Bistrihution. No label is attached to this sponge ; but it appears to have been 

 derived from the Upper Green Sand of Wiltshire. 



Genus CCELOCORYPHA, Zittel, 1878. 



C(ELOCOETPHA, Sp. 



Bistrihution. Cretaceous : St. Adresse. 



g2 



