IN THE LOWER TEETIAET STRATA OE jSTEW ZEALAND, 228 



'016 mm., thiclaiess of tubercles '0025 mm. This form is perhaps 

 only a variety of the preceding. 



Thoosa (a). — PI. XII. fig. 3. Spicule with short barrel-shaped 

 body, having above and below tliree curved obtuse processes 

 slightly furcate at the extremity which project outwards. At 

 either end of the body is a similar blunt process with terminal 

 spines, that at one end is slightly larger than the opposite one. 

 Length of spicule '03 mm., greatest width "02 mm. In its 

 general form this s])icule resembles the normal flesh-spicules of 

 Thoosa, but the tubercles are replaced by furcate and spined 

 processes. 



Sceptrelliform Flesh-Spicules of Ale ctona, Carter. 



PL XI. fig. 44. Spicule with straight subfusiform shaft, obtuse 

 at both euds, an expanded central portion with two whorls of 

 spherical bead-like bodies supported on short stalks, about eight 

 or nine in each whorl. The surface of the shaft is minutely 

 spined, and an axial canal extends through it opening at both 

 ends. Length of spicule '042 mm., width across whorls •Oil mm., 

 thickness o£ shaft '005 mm. This form corresj)onds very closely 

 with the flesh-spicule of Alectona {Corticium') WallicJii, Carter 

 (Ann. & Mag. Nat. Hist. s. 5, vol. iii. 1879, p. 353, pi. xxix. fig. 8). 



Spirular Flesh-Spicules of Spirastrella, Osc. Schmidt. 



Spirastrella (a). — PL XII. figs. 4, 5, Spicules with a short 

 sinuous shaft Irom w^hich large conical, obtusely pointed spines 

 project in difterent directions. Length of spicule "03 to -033 

 mm., thickness "Oil to 'OIG mm. These spicules so closely 

 resemble in form and size the flesh-spicules of Spirastrella cunc- 

 tatrix, Osc. Schm. (Algier. Spong. p. 17, t. iii. fig. 8), that they 

 might be considered to belong to this species, which is widely 

 distributed, Mr. Carter having recorded it from the Australian 

 Seas (Ann. & Mag. Nat. Hist. s. 5, vol. xvii. 1886, p. 113). They 

 also occur in the ' Egeria ' dredgings off the S.W. coast of Aus- 

 tralia at a depth of 2479 fathoms. The skeletal sj)icules of the 

 recent sponge are either pin-shaped or acuates, and of these there 

 are great numbers in the Oamaru material. Possil forms closely 

 similar are figured by Dr. Riist from the Jurassic strata of 

 Ilsede, Hanover (' Palseontographica,' Bd. xxxi. pi. xx. figs. 37, 38). 



Spirastrella (b). — PL XII. fig. 6. Spirule having a single 

 curve, the shaft is slightly swollen at the ends, which are thickly 



