A Revision of the Genus Aulacocliscus Ehrb. By J. Rattray. 349 



each with a cluster of 4 to 6 larger markings, and at outer end of each 

 ray is a small sharply defined area extending symmetrically on both 

 sides of process, and bearing coarse radial striae. Primary rays distinct, 

 the rows diverging slightly outwards. Border striae delicate, about 

 1/27 of radius broad. Processes 10, insertion about 1/16 of radius 

 from circumference, space at base small, hyaline. 

 Habitat : Moron deposit, Seville (Norman). 



§ 4. Akeolati. 



Slope to border sometimes steep. Inflations absent or rudimentary. 

 Markings pearly, central dot round or oval, distinct, rows radial, 

 slightly concave towards and adjoining primary rays. Primary rays 

 straight or with slight bendings. Border striated. 



A. apedicellatus sp. n. Aulacocliscus ? sp. — Sch. Atl.. pi. ciii. fig. 4. 

 —Diam. 0-085 to 0-225 mm. Surface flat for 1/3 to 2/3 of radius 

 and just within border, intervening slope steep. Colour pale slaty 

 grey, darker at outer edge of central area. Central space angular, 

 outline irregular, rarely regular, 1/30 of diam. broad, short diverticula 

 passing into apices of compartments; rarely somewhat excentric. 

 Markings polygonal, 4 in • 01 mm., rows deflected at origin of shorter 

 rows, rarely subfasciculate, secondary oblique rows evident. Primary 

 rays 7 to 13, distinct, sometimes asymmetrical, rows in contact, areolae 

 enlarging towards outer ends, where they are cuneate with long axis 

 oblique or radial. Border indistinct. Processes absent, but outer 

 ends of rays at 1/5 to 3/8 of radius from circumference, and opaque 

 when centre is in focus. 



Habitat : Simbirsk Polirschiefer (Kinker ! Cleve ! Kae !). 



A. celluhsus Grove & Sturt, Journ. Quek. Mic. CI., 1887, p. 8, 

 pi. ii. rigs. 8, 9. — Diam. 0*09 to • 23 mm. Surface, central portion 

 flat for 1/3 to 2/3 of radius, rarely almost to processes, with outer edo-e 

 bluntly angular and sides convex. Colour pale grey, darker towards 

 border. Centre with an inconspicuous rosette, 1/12 to 1/23 of diam. 

 broad. Markings large, irregular, polygonal, 2 to 3 in 0*01 mm., de- 

 creasing somewhat suddenly towards border, around the outer edge a 

 band of minute puncta, secondary oblique rows distinct. Primary 

 rays indistinct, rows in contact. Border striae sometimes oblique, 

 6 to 8 in • 01 mm., inner edge indistinct. Processes 4 to 9, insertion 

 1/9 to 1/12 of radius from circumference, constriction median, wide, 

 shallow, free ends rounded, no clear space at base. — A. cellulosus var. 

 plana Grove & Sturt, ibid., p. 140. 



The valves named var. plana Grove & Sturt are flat to processes 

 and the slope to the border is still more gentle. 



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



A. elegans Grove & Sturt, Journ. Quek. Mic. CI., 1887, p. 140, 

 pi. xii. fig. 30. — Sometimes subcircular, diam. 0*105 to 0*175 mm. 

 Surface flat to zone of processes, outer edge faintly angular at pro- 

 cesses; slope to border steep. Colour pale grey. Central space 



