382 Transactions of the Society. 



36. Primary rays short, V-shaped, markings small septus. 



„ „ obsolete, markings larger and more pearly .. .. Schmidt ii. 



37. A reticulum 38 



No reticulum 39 



38. Meshes large, unequal, often imperfect, with one distinct band 



at border, markings mostly oval and oblique reticulatus. 



Markings round 40 



40. Meshes smaller, subregular, in concentric bands, a few bands 



at border well defined, absent from most elevated zone . . Itogersii. 

 Meshes most evident and scale-like on flat peripheral portions 



of compartments Grunowii. 



39. Inflations absent or slight 41 



„ present, low, mammillate beneath processes .. .. 42 



41. Process large, proximal portion much smaller than distal, clear 



space at base well marked ; a central rosette sollittianus. 



No rosette 43 



43. A sharply defined polygonal area from centre to processes, its 



outer edge steep and sides straight across compartments . . secedens. 



Markings large, brilliant, with distinct central or unilateral 



dot, processes with well-marked clear space at their base .. margaritaceus. 



Markings smaller, less brilliant, the rows at middle of compart* 

 ments together forming an inconspicuous cross; primary 

 rays cruciform with slight inflations at outer ends; pro- 

 cesses small, with clear space at base minute crux. 



Most elevated zone at processes narrow angular 44 



44. With prominent, hyaline, irregular, radial spaces on most 



elevated zone radiatus. 



No such spaces 45 



45. Marking round, large, distinct Huttonii. 



„ polygonal, small, indistinct, valve transparent . . .. pallidus. 



42. Processes long, narrow, cylindrical amcenus. 



„ conical, large, outer edge of sculptured area undulate intumescens. 



„ with lateral median constriction 46 



46. Markings in regular concentric bands orientalis. 



No such bands 47 



47. Markings in irregular angular subconcentric bands towards 



central space ; primary rays indistinct affinis. 



No such bands ; primary rays well-marked, more opaque . . oregonus. 



34. Primary rays on a level with adjoining surface hilkellyanus. 



„ „ raised on inflations 48 



48. A distinct lobe at sides of outer ends of inflations rotulus. 



No such lobes 49 



49. Conspicuous bent subradial or oblique irregular interspaces on 



outer portion of valve ; outer ends of inflations bounded by 



prominent dark curved lines anthoides. 



No such interspaces 50 



50. Coralloid markings on sides of inflations grevilleanus. 



No such markings 51 



51. Most elevated zone sharply defined, narrow angular .... 52 



„ „ less sharply denned, sometimes wide .. 53 



52. A reticulum evident superbus. 



„ just visible attenuatus. 



No reticulum, irregular ridges on inflations archangelskianus. 



53. Processes with proximal portion rounded, distal cylindrical . . spectabilis. 



„ biconvex on each side 54 



54. Slope of primary rays from highest zone to processes steep ; 



interspaces punctate angulatus. 



Slope of primary rays from highest zone to processes gentle ; 



interspaces hyaline decorus. 



