908 Transactions of the Society. 



Highest zone indistinctly defined ; markings punctate in railial 



rows only pulvinalus 



No such zone 3 



3. Border t;liari)ly defined 4 



„ inconspicuous 5 



4. Markings minute, areolatc, in radial and oblique rows ; apiculi 



3 to 7 between adjoining processes, prominent .. Petili 

 „ granular, increasing towards the border, non-fascicu- 

 late. Border striated radiatus 



„ areolate, row t; fasciculate, the converging rows sharply 



curved near the processes peruvianus 



5. Surface convex. Processes minute. Markings delicate, areolate, 



in radial and oblique decussating rows. Processes 2 letonensis 



„ almost flat. Processes large 6 



„ with a cuneate inflation tapering inwards from each of 

 the 4 processes. Markings areolate, 4 in O'Ol mm., 



most evident on tlie inflations tetrnophthalmus 



6. Markings areolate, 4 in 0' 01, non-apiculate amh/guus 



„ „ 8 in 01 mm., rows visible only at pro- 

 cesses, apiculi prominent hirsuius 



„ granular 7 



„ more minute, punctate, or forming delicate strise . . 8 



7. Rows radial, striae converging to processes short, a circlet of 



distinct apiculi at border ; no reticulum .. .. Dthiji 



„ „ a large meshed reticulum ruljdanus 



„ short, radial, indistinct near border, elsewhere markings 



irregular notatus 



8. A zone round each process punctate, outside of this zone short 



curved striaj, centre punctate elaboratus 



No such zone 9 



9. Markings punctate, irregular at centre, in faint oblique lines 



near processes ; low mammillations beneath the 



processes. Processes 4 johnsonianut 



„ striate in subregular order. Valve apiculate . . .. 10 



„ punctate, without order. Valve non-apiculate .. 11 



10. Apiculi evident, absent from a small central area. Processes 2. 



Markings in radial rows diffmus 



„ minute, but numerous. Markings subpruinoso in 

 conspicuous close radial strire, those converging to 



the processes short, more evident ancepa 



„ faint, chiefly near border. The four sets of con- 

 verging striaj meeting at centre and at middle of 

 space between adjoining processes nehuloxns 



11. Markings largest at centre. Processes 5 ornatus 



A pentiigonal clear central area with sides concave and angles 



reaching tlie processes rotatua 



MONOPSIA Grove & Sturt. 



Monopsia Grove & Sturt, Journ. Quek. Mic. CL, 1887, p. 141. 



Yalves circular. Surface rising gradually towards the process. 

 Colour pale yellowish grey. Central space absent. Markings, delicate 

 closely-placed striae radiating from the edge of the process to the 

 border, but less evident on a narrow distinct band contiguous to the 

 border, minute scattered apiculi irregularly disposed, or most abundant 

 near the inner edge of the marginal band. Process single, eccentric, 

 circular, with a single band of distinct elliptical gi-anules, having the 

 long axes radial about its semiradius, the outer portion finely striated, 

 the free end almost flat. 



