IN THE LOWER TERTIARY STRATA OF NEW ZEALAND. 185 



spicules occur in Haliclwndria infrequens. Carter (AiDn. & Mag. 

 N. H. s. 5, vol. vii. 1881, p. 369, pi. xviii. fig. 9 «), from the Gulf 

 of Manaar. 



PI. VII. fig. 16. Acerate, fusiform, nearly straight, gradually 

 tapering to acutely pointed extremities. Surface witli strong 

 stout spines projecting at right angles, irregularly distributed. 

 Length '076 mm. by "014 mm. in thickness, including the spines. 

 Similar spicules are present in Sclerilla dura, Hansen (Norw. 

 ]S"orth-Atl. Exp., Spong. pi. ii. fig. 5). 



PI. VII. fig. 17. Acerate, fusiform, slightly arcuate, ends 

 abrupt and very acute. Spines disposed verticillately, the largest 

 in the central |)ortion are directed outwards, those near the ends 

 are slightly recurved. Length "14 mm., thickness '025 mm. 



Pi. VII. fig. 18. Acerate, fusiform, a slight inflation in the 

 centre, from which the straight rays diverge at an open angle. 

 A continuous axial canal. Spines very small, sparsely and 

 irregularly distributed. Length "14 mm., thickness '015 mm. 

 Rare. Spicules similar in form but without spines occur in 

 Salichondria aceratospicultim, Carter, from the Gulf of Manaar 

 (Ann. & Mag. N. H. s. 5, vol. vi. 1880, p. 49, pi. v. fig. 19 5). 



PI. VII. figs. 19, 22. Acerate, fusiform, with a strongly-marked 

 bend in centre, acutely pointed. Spines numerous, small, 

 blunted, irregular!}'' distributed, projecting at right angles. 

 Length "175 mm., thickness "015 mm. Similar but slightly 

 smaller spicules are present in the dermal membrane of Hyme- 

 desmia injiata. Bow. (Mon. Brit. Spong. vol. iii. p. 248, pi. 79. 

 fig. 8), from Slietland. 



PL VII. fig. 20. Curved acerate, nearly cylindrical throughout 

 its length, with abruptly pointed ends. Surface thickly covered 

 virithsmall irregularly distributed spines, which are more numerous 

 near the centre than at the ends of the spicule. Length '2 mm., 

 thickness "Oil mm. 



PI. VII. fig. 21. Slender, fusiform, slightly contort, gradually 

 tapering to acute points ; surface annulated with smooth rings, 

 those near the ends minutely tuberculate. Length "255 mm., 

 thickness '01 mm. Mr. Carter figures similarly annulated 

 spicules in Hymerhapliia eruca (Ann. & Mag. N. H. s. 5, vol. vi. 

 p. 46, pi. iv. fig. 9 b), from the Gulf of Manaar. 



PI. VII. fig. 41. Acerate spicule with straight subcylindrical 

 or subfusiform shaft and obtusely conical exti'emities. The 

 shaft has irregularly scattered stout spines — those in the centre 



