— 23 — 

 Reniera, sp. 



(Plate I, figs. i6, 17). 



Spicules of a cylindrical form, curved, uniform in calibre 

 throughout and rounded at both ends. Exterior surface ori- 

 ginall)- smooth. Canals obliterated , but in similar spicules 

 from the Wcstphalian Chalk a simple cylindrical canal traver- 

 ses the spicule. There are two well marked forms of these 

 spicules; the one (fig. 16), longer and proportionally much 

 thinner than the other, has a length of 0.517 mm. by 0,056 mm. 

 The shorter (fig. 17) form, in some specimens almost kidney 

 shaped, is 0,33 mm. long by 0,112 mm. wide. Specimens of 

 both forms are not uncommon. 



Spicules of existing sponges, nearly approaching in form 

 to these, have been discovered by Mr. Carter in species of Re- 

 niera from the Gulf of Manaar; (An. and Mag. Nat. Hist. 

 S. 5, \'ol. 6, p. 478, PI. V, fig. 18). Cylindrical spicules 

 have also been figured by Oscar Schmidt in a sponge from 

 the Atlantic, Siibcritcs arciger (Atlant. Spong. p. 47, Taf. V, 

 fig. 6). Cylindrical spicules similar in form but of larger 

 size have lately been discovered by Mr. Carter in Irish Carboni- 

 ferous strata (An. and Mag. S. 5, Vol. 6, p. 212, PI. XIV, 

 fig. 14). They are present also in the Chalk Strata of Coes- 

 feld. (Ueber Coelop. p. 40, Taf IV, figs. 38 — 43) and in the 

 Green Sand at Haldon (An. and Alag. Nat. Hist. S. 4, Vol. 7 

 PI. IX, fig. 53). 



Scolioraphis? sp. 



(Plate I, fig. 5). 



Very elongated, sinuous .spicules, apparently cylindrical, 

 of the same thickness throughout their length, irregularly bent 

 and fractured at their extremities. A central canal is exhibited 

 in some .specimens. The surfaces of these spicules are far 

 more eroded than any others in this flint-meal, and forameni- 

 feral shells and other small objects frequently adhere to them, 

 so that they have an altogether diflferent aspect to any other 



