332 



A. W. WATERS ON FOSSIL CBIL0ST0MAT0TT8 



indicated Leprcdia ; but the interior shows that the lower edge of 

 the operculum was straight, and that it must be placed with Micro- 

 porella. 



37. Microporella stmmetrica, sp. nov. Plate XVIII. fig. 83. 



Zoarium in Escliar a- form, foliaceous. Zooecia hexagonally oval, 

 distinct, with a thin border round the cell, scarcely raised, with few 

 pores near the edge, raised in the region of the aperture, especially 

 above the aperture. Two large openings, directed laterally imme- 

 diately before the aperture ; these are usually raised and form part 

 of the peristome. An area on the lower part of the cell with stellate 

 pores arranged in two series of 4 or 5, each regularly opposite to one 

 another ; sometimes one or two pores between the lateral rows. This 

 area usually forms a deep depression ; but in some cells this is not 

 the case. Oral aperture semicircular, with straight proximal edge, 

 0*09 mm. wide, 0*07 mm. long. 



In the species we see a marked likeness to M. yarraensis (fig. 27) ; 

 and through these we are able to trace the relationship of this area 

 from the round pore of M. violacea to the elongate pore of M. violacea, 

 var. fissa (fig. 26), to the two or three pores of M. yarraoisis, and 

 the cribriform pores of M. coscinopora (fig. 25) and M. cenigmatica 

 (figs. 29, 30), and, lastly, to the depressed area of the present species ; 

 and we seem justified in extending the comparison and comparing 

 the non-depressed area of the present with that of Cribrillina 

 terminata (fig. 68), which, in its turn, may be traced to typical 

 Cribrillina. 



38. Microporella clavata, Stol. Plate XVIII. fig. 84. 



Flustrella clavata, Stol. Poss. Pry. Orak. p. 139, pi. xx. figs. 3, 5. 



Zoarium in Eschara-ioxm, forming thin foliaceous dichotoinous 

 branches or small round branches. Zooecia suboval, contracted and 

 truncate below; a characteristic semicircular depression immediately 

 below the aperture, with three large raised pores, the two upper 

 ones directed to the right and left. A laterally oval depression or 

 opening about the middle of the zocecium, with the median pore 

 below this. Oral aperture semicircular, with a straight proximal 

 edge. 0*07 mm. wide, 0*05 mm. long. 



This is much the same as Eschara tetrastoma, Ess. Sitz. Ak. W. 

 Wien. 1864, p. 9, pi. ii. fig. 9. 



Loc. Possil : Orakei Bay. 



39. Porina cltpeata, sp. nov. Plate XVII. fig. 67. 



Zoarium erect, cylindrical ; four zooecia in a complete series, al- 

 ternating regularly with each other, and facing in four directions. 

 Zooecia distinct, tubular ; peristome much projecting ; median pore 

 placed about one half the length of the cell, opening at the top of a 

 cone, the base of which is surrounded by an oval or circular rim, 

 giving it a shield-like appearance. This rim is continued in a straight 

 line above and below. A small obtuse avicularium on each side of 

 the shield-like boss. 



