Vol. 55.] DEVONIAN EOCKS OF NEW SOUTH WALES. 53 



Order DISCOIDEA, Haeckel. 



Genus Theodiscfs, Haeckel. 



The test is a simple latticed disc, with three marginal radial 

 spines at equal or unequal distances apart. 



Theodisctjs ha status, sp. nov. (PL IX, fig. 9.) 



Test small, with rounded pores and slender, polygonal lattice- 

 bars. Radial spines robust, keeled, and acutely pointed, at unequal 

 distances apart. Diameter of test, 0*075 mm. ; width of lattice-pores, 

 0-005 mm. ; length of spines, 0*08 to 0*15 mm. ; thickness at base, 

 0-025 mm. In volcanic tuff. No. 387 d. 



Genus Trochodiscus, Haeckel. 



The test is a simple latticed disc, with ten or more marginal 

 radial spines. 



Teochodiscus planattjs, sp. nov. (PI. IX, fig. 10.) 



Test compressed, with rounded subequal pores and bars about 

 half the w^idth of the pores. A number of stout, short, conical 

 spines extend from the margins. In the centre of the test is a 

 minute three-rayed spicule, closely resembling the detached forms 

 which have been referred to Sphcerozoum. Diameter of test, 

 0-17 mm. ; width of lattice-pores, O'Ol mm. ; length of spines, 0-02 

 to 0-05 mm. In siliceous limestone. J^o. 245 3. 



Genus Triactisctjs, Haeckel. 



The latticed disc has a simple medullary test, and three radial 

 spines on the margin. 



Teiactiscus lanceola, sp. nov. (PI. IX, fig. 11.) 



The cortical test has very minute rounded pores ; the lattice-bars 

 are nearly as wide as the pores, and are furnished with minute 

 spines. The medullary test is only indicated by a fragment of the 

 mesh, with pores larger than those of the cortical test. Of the radial 

 spines only two are preserved, and one of these is imperfect ; the 

 other is lanceolate in form, with a strong longitudinal keel. 

 Diameter of cortical test, 0*105 mm. ; width of pores, 0-005 mm. ; 

 radial spine : length, 0-115 mm., and greatest width, 0-04 mm. In 

 volcanic tuff. No. 387 n. 



Genus Disteiactis, Haeckel. 



The latticed disc has a simple medullary test, and six radial 

 spines extending from the margin in the equatorial plane. 



Disteiactis vetusta, sp. nov. (PI. IX, fig. 12.) 



Both the outer and inner tests are oval in outline ; the pores of 



