IJf TIIK LOWER TEETIAEY STRATA OF NEW ZEALAND. 247 



across spicule "16 mm., length of rays "08 mm., thickness •OOG mm. 

 Many of tlie rays are now fractured ; it is probable that when 

 complete there may have been from 30 to 40. Eosettes somewhat 

 smaller, but with rays of the same character as this fossil, are 

 present in Crateromorpha tumida, Schulze (Chall. E<ep. vol. xsi. 

 p. 166, pi. 67. fig. 6), from near the Banda Islands, at a depth of 

 360 fathoms. 



CrateromorpJia (b). — PI. XV. fig. 13. Rosette of the same 

 character as the preceding, but tlie rays are much more robust 

 and somewhat shorter in proportion. The convex discs capping 

 the rays are fringed with teeth. The rays appear to start from 

 a thickened globate centre; most of them are now incomplete, 

 but judging by the stumps that remain there would have been 

 from 30 to 40 originally. Length of rays '0875 mm., thickness 

 at base "0125 mm., width of capitate disc '025 mm. The rays of 

 this rosette are much stouter than in any recent spicule of this 

 type. 



AmpMdisc Spicules of Hyalonema, Gray, and 

 Pherouema, Leidi/. 



Hyalonema (a). — PL XV. fig. 14. Amphidisc with four rays, 

 as if two of the normal forms had been welded together by the 

 shafts. The shafts are elongate, slightly inflated where they are 

 united, and with a few scattered tubercles. The terminal rays, 

 about six in number at each end, are strap-shaped, irregularly 

 curved and twisted, occasionally bifurcate and openly divergent. 

 Diameter of spicule "22 mm., width across rays "101 mm., thick- 

 ness of shaft '009 mm. This peculiar spicule may be only au 

 abnormal form. Amphidiscs with four rays are, however, present 

 in the recent Hyalonema tenerum, Sch. (Chall. E,ep. vol. xxi. 

 pi. xxxi. fig. 18). 



Hyalonema (b). — PL XV. fig. 15. Amphidisc with elongate 

 slender shaft, with a subcentral whorl of nodes, the surface with 

 small tubercles. Head-rays about six in number at each end, 

 elongate, Ungulate, nearly straight or slightly curved towards 

 the shaft. Length of spicule "189 mm., width across head-rays 

 •04 mm., length of rays "065 mm. In the comparatively small 

 number of the rays this form is distinct from any of the recent 

 amphidiscs figured in the ' Challenger ' Report ; the nearest 

 approach to it is the large amphidisc in Hyalonema lusitanicum, 

 Bocage (see Chall. Rep. vol. xxi. pi. xxviii. fig. 14). 



