194 DR. HIXDE A^B MB. HOLMES ON SPONGE-REMATKS 



PI. IX. fig. 12. Spinulate, with well-marked rounded head ; 

 straight, fusiform, smooth shaft, acutely pointed. Length '15 mm., 

 thickness '013 mm. Similar spinulates occur in Froteleia SoUasi, 

 Ridley and Dendy (Chall. Rep. vol. xx. p. 214, pi. xlii. figs. 8 e, 8/), 

 from Simon's Bay at a depth of 10-20 fathoms. 



Pi. IX. fig. 19. Small, slender spinulate, the upper portion 

 curved ; shaft slightly fusiform, smooth. Length '115 mm., 

 thickness *006 mm. 



PI. IX. fig. 14. Approximately straight, smooth ; head evenly 

 round, not constricted ; shaft gradually tapering to an acute 

 point. Axial canal shown as a very delicate even thread, not in- 

 flated at the head. Length '513 mm., greatest thickness "045 mm. 



PI. IX. figs. 15-18. Straight nail-like spinulates, M'ith rounded 

 well-defined heads, which are either covered with blunted spines 

 or tubercles or quite smooth ; the shafts taper from the head 

 and are spined throughout ; the spines in the upper portion 

 projecting at right angles, whilst lower down the shaft they 

 are oblique, pointing to the head of the spicule. Length "085 to 

 •175 mm., thickness of shafts "005 to "02 mm. Spined spinulates 

 resembling these are figured by Bowerbank in the recent Hyjne- 

 rapTiia clavata and in S. simplex (Mon. Brit. Spong. vol. iii. 

 pi. xxvi. fig. 9, pi. Ixxx. fig. 3) ; and Dr. Eiist figures a similar 

 form from the Jurassic strata of Ilsede, Hanover (Palaeonto- 

 graphica, Bd. 31, pi. xx. fig. 5). 



PI. YIII. figs. 37, 37ff, 38. Spicules straight, nail-like in form ; 

 heads rounded or flattened, with very prominent spines, pro- 

 jecting horizontally or recurved, sometimes with a verticillate 

 arrangement ; shafts gradually tapering to an acute point, pro- 

 vided with minute spines directed upwards towards the head of 

 the spicule. Length -073 to "116 mm., thickness '006 to '01 mm. 

 Somewhat similar spinulates are figured by Bowerbank in Sy- 

 meraphia coronula (Mon. Brit. Spong. vol. iii. p. 246, pi. Ixxix. 

 figs. 3, 4). A form similar to 37a is figured by Osc. Schmidt in 

 Stelletta pumex (Adriat. Spong. Suppl. i. p. 32, pi. iii. fig. 9 a); 

 but that it really belongs to a species of Stelletta is very doubtful. 



Abnormal Spinulate. 



PI. VIII. fig. 29. Spicule with subcylindrical curved shaft, at 

 the head of which several prominent rounded tubercles are 

 grouped. The axial canal has a small bulbous inflation at the 



