IK THE LOWER TERTIARY STRATA OF NEW ZEALAND. 197 



are present in AmpJiilectus pilosus, Ridley and Deudy (Chall. Eep. 

 vol. XX. p. 126, pi. xix. fig. 5 b), from ^Kerguelen at depths of 50 

 to 70 fathoms. 



PL IX. fig. 24. Tricurvate, smooth, with open central curve, 

 extremities pointed. Length "096 mm., thickness "006 mm. A 

 similar but slightly longer spicule is figured by E-idley in Amphi- 

 lectus tibiellifer (' Alert ' E.ep. p. 428, pi. xlii. fig. t), from 

 Torres Straits. 



Tricurvate spicules are of I'are occurrence in the Oamaru 

 material. Though the forms described are referred to AmpM- 

 lectus, the same kind of flesh-spicule is common to Desmacidon, 

 Esperella, Samacantlia, and other genera of recent sponges. 



Hoolc-sJiaped or Bihamate Flesh-Spicules o/" Esperella, Vosmaer, 

 and other Genera. 



PI. IX. fig. 25. Spicule slender, C-shaped, nearly of an even 

 thickness throughout, regularly curved. Height '076 mm., thick- 

 ness "003 mm. 



PI. IX. fig. 26. Small, slender, abruptly curved in the centre, 

 ends acute, sharply bent inwards. Height '05 mm., thickness 

 •003 mm. 



PI. IX. fig. 27. Spicule C-shaped, very evenly rounded. 

 Height '13 mm., thickness '006 mm. This form resembles the 

 hook-spicules of GelUus glacialis, Eidley and Dendy (Chall. Rep. 

 vol. XX. p. 41, pi. xiii. figs. 12, 15), from the Agulhas Bank at a 

 depth of 150 fathoms. 



PI. IX. fig. 28. Spicule stout, very openly curved, partly 

 contort, ends acute, curved inwards. Height '205 mm., thickness 

 •01 mm. 



PI. IX. fig. 29. Spicule small, evenly curved, ends very acute. 

 Height "06 mm., thickness '003 mm. 



PI. IX. fig. 30. Stout spicule, C-shaped, ends contort, sharply 

 bent inwards. The axial canal distinctly shown, traversing the 

 specimen and opening at the ends. Height "185 mm., thickness 

 'Oil mm. Similar but somewhat larger spicules are present in 

 Cladorhiza moruliformis, Ridley and Dendy (Chall. Rep. vol. xx. 

 p. 90, pi. xxi. fig. 15), from the Southern Ocean, south-west of 

 Australia, at a depth of 1950 fathoms. 



PI. IX. fig. 31. Small hook-shaped, ends contort, abruptly 

 bent, acutely pointed. Height -043 mm., thickness "0026 mm. 



PI. IX. fig. 32. Stout hook-shaped, ends evenly but narrowly 



