366 Transactions of the Society. 



gonal, 5 to 6 in 0*01 mm., rows straight only at middle of com- 

 partments; apiculi irregular, round, about outer 2/3 of primary- 

 rays, absent from central area and intervening areas of compartments. 

 Primary rays with rows diverging slightly in outer half. Border 

 striae 10 in • 01 mm., 1/18 to 1/27 of radius broad, a delicate marginal 

 undulation. Processes 4 or 5, insertion 1/3 to 1/5 of radius from 

 circumference, proximal portion smaller than distal, constriction 

 shallow, about 1/3 of length from base, striae distinct, clear space at 

 base minute, length 1^ to 2 times breadth. — Sch. AtL, pi. xxxv. fig. 4, 

 pi. xli. figs. 1-2. Eupodiscus Petersii Kiitz., Sp. Alg., p. 135. 

 E. crucifer, Shadb., Trans. Mic. Soc. Lond., 1854, p. 16, pi. i. 

 fig. 12. 



Habitat : Mouth of Zambesi Piiver, East Africa (Ehrenberg) ; 

 Algoa Bay guano (Dickie ! O'Meara !) ; Natal (Johnson !) ; South 

 African guano (Greville ! Eae !) ; Cambridge deposit, Barbadoes 

 (Greville ! Hardman !) ; Newcastle deposit, Barbadoes (Firth !) ; New 

 Zealand (Johnson ! Arnott !) ; Teneriffe (Greville !) ; Tamatave 

 (Hardman !) ; Nankoori (Cleve !). 



Var. asperida. A. crucifer Shadb. ? Sch. Atl., pi. xli. fig. 4. — Diam. 

 • 18 mm. Surface flat to about 2/7 of radius, inflations much larger 

 at outer extremity, equal in breadth to radius, edges straight. Central 

 space irregularly angular, about 1/36 of diam. broad. Markings, 

 apiculi prominent and large about middle of inflations, less evident 

 towards their margins, minute, on a zone of irregular breadth close to 

 border. Border striae coarser, 8 in 0*01 mm., inner edge sometimes 

 distinct. Processes 4, insertion 1/3 to 1/4 of radius from circumfer- 

 ence. — A. Petersii 'Ehrh. according to Grunow and Witt fide Schmidt, 

 Atl., pi. cii. fig. 6. The scar of broken-off process is elliptical. 



Habitat : Simoda, Japan (Weissflog !). 



Var. notahilis. A. Petersii Ehrb. var. ? Sch. Atl., pi. xxxv. figs. 

 1-3. — Diam. ■ 11 to • 265 mm. Surface, outer edge of central area 

 more concave outwards than in type, inflations rising more steeply, 

 crests flattened near processes, outer ends sometimes reaching border, 

 intervening portions of compartments almost flat from central area for 

 about 3/10 of radius. Central space minute, 1/32 to 1/60 of diam. 

 broad. Markings 6 to 8 in 0*01 mm.; apiculi numerous on central 

 area, inflations fewer and inconspicuous on intervening portions of 

 compartments. Processes 5 to 7, insertion 1/4 to 2/5 of radius from 

 circumference, length about If times breadth. 



Habitat : California (Schmidt ! Weissflog ! Eae !) ; Colon and 

 Vera Cruz (Hardman !). 



Var. expansa. — Valve rarely elliptical, diam. 0*105 to 0*29 mm. 

 Surface with inflations tapering rapidly towards centre, peripheral 

 area flat, its edge convex inwards between inflations. Markings, 

 apiculi minute, continued on inflations to centre, rarely on central 

 space, on intervening portion of compartments confined to an 

 irregular marginal band extending to angles of inflations. Border 

 striae 8 in • 01 mm. Processes 4, insertion 1/4 to 1/7 of radius from 



