179 



EXPLANATION OF PLATE. 



Fig. I. Microsclcroclcniici liirsntniii, sp. n. ^ natural size. 

 Id. Outer or poral surface. Natural size. 

 1 6. Section, x 3. 



ic. Two monocrepid desmas, x 100, 

 id. Oxea, x 100. 



IC. Sigmaspires, x 700. (The terminal thickenings do not 

 reallv exist, and disappear on focussing). 



Fig. 2. Discodcniiid luiUdcnsis, sp. n. f natural size. 

 2ii. Outer or poral surface, x 80. 

 26. Inner or oscular, x 80. 

 2c. Phyllotriaene of poral surface, x 100. 

 id, c. Discotriaenes of oscular surface, x 100. 

 if. Small tyle, x 420. 

 ig. Oxea, X 420. 

 ih. Style, X420. 

 ij. Microxea, x 700. 

 ik. Microstrongyles, x 700. 



Fig. 3. Discodcnnia luitcdcnsis, a much worn specimen, 

 f natural size. 

 yiy h. Tetracrepid desmas, x 100. 

 3c. Style, X 100, 

 3<7. Microstrongyles, x 700. 



Fig. 4. Section of wall of specimen drawn in Fig. 3, slightly 

 enlarged, showmg a patch (lighter in shading) of Trip- 

 tolc'inus inceiiiis, sp. n., in the midst of the Lithistid 

 skeleton of the Discodcymia. 



Figs. ^(i-d. Centrotriicnes, x 100. 

 t\c. Microxea, x 100. 

 4/. Metaster, x 1625. 



