A Revision of the Genus Aidacodiseus Ehrh. By J. Rattray. 361 



7 to 12, insertion 1/5 to 1/7 of radius from circumference, cylindrical, 

 free ends flat or slightly convex, clear space at base minute. 



Habitat : Sta. Monica deposit (Johnson ! Weissflog ! Eae ! Cleye ! ) ; 

 Sta. Maria deposit (Grove! Kae!) ; San Pedro (Kinker!). 



Var. sparse-radiata. — Diam. ' 185 mm. Surface flat at central 

 space, from this rising for about 5/12 of radius to highest zone, the 

 latter about 1;4 of radius broad, convex; slope to border more steep. 

 Markings in more widely placed parallel rows, attenuated at periphery 

 for 1/20 to 1/25 of radius, with short rows in the intervals. Pro- 

 cesses 11, insertion 1/7 to 1/8 of radius from circumference. 



Habitat : Sta. Maria deposit (Rae !). 



A. orientalis Grev., Trans. Mic. Soc. Lond., 1864, p. 12, pi. ii. 

 fig. 6. — Diam. ■ 095 to 0'35 mm. Surface rising for 2/7 to 4/9 of 

 radius, thence flattened to highest zone, the latter 1/14 to 2/9 of radius 

 broad, concavities between processes well marked. Colour deep brown 

 on central space, elsewhere slaty grey, rarely hyaline. Central space 

 round, 1/17 to 1/19 of diam. broad, usually granulate. Markings 

 quadrate to outer edge of highest zone, 4 in 0*01 mm., beyond this 

 rounded, rows straight, radial, deflected at processes, secondary 

 regular concentric bands obvious. Primary rays obvious. Border 

 with coarse striae, inner edge indefinite. Processes 7 to 45, insertion 

 1/6 to 1/23 of radius from circumference, proximal and distal parts 

 subequal, constriction median, slight, length 1^ to 2 times breadth. 

 — Sch. Atl., pi. xxxiv. figs. 1-3. A. orientalis var. nanhoorensis 

 Grun., Eeise d. Novara (Bot. Th.) Bd. i. p. 103. 



The scar of the broken-off process is roundly elliptical. Some- 

 times confounded with A. or eg onus. Stodder has described its central 

 space as bluish green. 



Habitat: Sandwich Islands (Greville! H. L. Smith, Weissflog!); 

 Ceylon (O'Meara ! Macrae ! Clive !) ; Eimio (Hardman !) ; Point de 

 Galle Ceylon, Vega Exp. (Cleve ! Weissflog!); N. Celebes (Griindler) ; 

 Labuan (Cleve!); Nicobar Islands (Macrae!); "Indian Ocean" 

 (Macrae!); pearly shell debris loc. (?) (Norman!); off Philippine 

 Islands, 705 mis. (Piae !). 



§ 8. Inflati. 



Surface flattened at centre ; inflations large, sharply circum- 

 scribed, inner ends merging with raised central area. Primary rays 

 distinct. 



A. gracilis sp. n. — Diam. 0'095 mm. Surface flat to 7/19 of 

 radius, thence primary rays rising to processes ; inflations evident only 

 at outer ends. Colour transparent, outer ends of inflations light grey. 

 Central space indistinct, about 1/13 of diam. broad, an irregular granule 

 at its centre. Markings round, 4 in • 01 mm., or compressed, out- 

 lines faint but distinct at outer ends of primary rays, rows parallel. 

 Primary rays straight, rows diverging at outer ends. Border indis- 

 tinct, a narrow hyaline space adjacent to it opposite compartments. 



