AXINELLA. 145 



forms. On weathered surfaces of these beds the spicules have the appearance of 

 a closely felted mass of delicate threads. 



Distribution. — Yoredale series : near Harrogate, Yorkshire; Trelogan, Gronant, 

 Flintshire. Upper Limestone series : Benachlan, Fermanagh. 



Genus. — Axinella, 0. Schmidt. 

 1862. Die Spongien des adriatisehen Meeres, p. 60. 



Branching fibrous Sponges. Spicules acuate or acerate, straight or curved. 

 In the axial portion of the Sponge the spongin is more developed than near the 

 periphery (Vosmaer). 



The genus is based on Sponges now existing in the Mediterranean. Entire 

 fossil forms are unknown, but detached spicules, closely resembling those of 

 existing species, are present in Carboniferous strata and more abundantly in the 

 Greensand and Chalk, and may provisionally be referred to the genus. 



26. Axinella vetusta, Hinde, sp. nov. Plate IV, fig. 6. 



The spicules included in this species are smooth, robust acuates, with evenly 

 rounded summits, gently curved, retaining an equal thickness for about one half 

 their length, then gently tapering to an obtuse point. The specimen figured is 

 2*3 mm. in length by '2 mm. in thickness. 



This form of spicule is not known earlier than in the Carboniferous Rocks, where 

 it is of rare occurrence. 



Distribution. — Carboniferous Limestone : Clitheroe, Lancashire. Upper Lime- 

 stone series : Glencart, Dairy (J. Smith). 



27. Axinella paxillus, Hinde, sp. nov. Plate IX, fig. JO. 



The spicules in this form are smooth, nearly or entirely straight, of an even 

 thickness for two-thirds of their length, then gradually tapering to an obtuse 

 point. The summit is slightly inflated. An average specimen is 1*45 mm. in 

 length by "08 mm. in thickness. 



This form approaches closely to spicules included in Axinella stylus, Hinde 



