364 Transactions of the Society. 



flatus var. Huttonii, Grim., Bot. CentralbL, Bd. xxxi. No. 5, p. 133 ; 

 A. Huttonii Grun. in litt. 



Habitat : Oamaru deposit, New Zealand (Grove & Sturt ! Rae !). 



Var. areolata. — Diam. 0'26 to - 4 mm. Surface, outline of 

 central portion less marked, inflations distinct only near outer ends, 

 narrow, radial, clear areas absent. Colour pale grey, smoky grey 

 at border, bluish at outer ends of inflations. Central space round, 

 about 1/26 of diam. broad, at its middle a quadrate punctate spot. 

 Markings rounded towards centre, polygonal with outlines distinct 

 in outer portion, 4 in 0*01 mm., reticulum of irregular meshes well 

 marked on outer 5/13 of compartments. Primary rays with rows 

 diverging in outer 1/3 of length. Border striae 8 in 0*01 mm., 

 inner edge indistinct. Processes 7, insertion about 1/10 of radius 

 from circumference, cylindrical, free ends truncate, length about twice 

 breadth. 



Habitat : Oamaru deposit (Grove ! Doeg !). 



A. carruthersianus Kitton & Grove, MS. — Diam. 0*185 to 

 0'2 mm. Surface flat to 2/7 of radius. Primary rays rising 

 gradually from this to their flattened central portion, thence sloping 

 slightly downwards to processes ; inflations with outer ends rounded, 

 sides faint; areas between inflations flat at middle with outer 

 edge distinct, convex outwards ; slope to border steeper opposite 

 processes and middle of compartments than elsewhere. Colour pale 

 grey. Central space irregularly quadrangular, 1/25 to 1/40 of diam. 

 broad, hyaline. Markings polygonal, 4 in • 01 mm., rows sometimes 

 curved at inflations. Primary rays with markings muriform, rows 

 diverging slightly near outer ends. Border striae coarse, 6 in • 01 mm., 

 sometimes with irregular short protuberances. Processes 4, insertion 

 1/6 of radius from circumference, hourglass-shaped, clear space at 

 base small. — PL V. fig. 7. 



Habitat : King George's Sound (Grove ! Weissflog !) ; Newcastle 

 deposit, Barbadoes (Rae !). 



A. aucMandicus Grun., Sch. AtL, pi. xli. fig. 3.— Valve rarely 

 elliptical. J)iam. • 07 to • 155 mm. Surface, central portion flat for 

 2/7 to 1 /4 of radius, with outer edge convex or almost straight across 

 compartments, primary rays on same plane or rising slightly from 

 edge of the central portion to processes, outer ends of inflations 

 merging gradually into peripheral area. Colour dark grey, sometimes 

 bluish at centre. Central space subquadrate or irregular, 1/16 to 

 1/18 of diam. broad, hyaline or with faint granules. Markings poly- 

 gonal, 5 in 0*01 mm., without interspaces. Apiculi large, rounded, 

 irregular, most distinct within and near processes, rare on intervening 

 portions of compartments, variable on different inflations of same valve. 

 Primary rays with rows diverging but little but often of different 

 lengths. Border striae 8 to 10 in 0*01 mm., 1/13 to 1/26 of radius 

 broad. Processes 4, rarely 3 or 5, insertion 2/7 to 3/8 of radius from 

 circumference, proximal portion subelliptical, distal with edges diverg- 

 ing, rarely converging outwards, around each a narrow crescentric line. 



