882 Transactions of the Society. 



A. pruinosus Bail. Smiths. Contrib., 1853, p. 5, pi., figs. 5-8. 



Circular or subeircular, diam. 0* 0675 to 0"13 mm. Surface 

 rising slightly near the processes, slope at border gentle. Colour pale 

 or pale smoky grey. Central space rounded, • U05 to "0075 mm. 

 bro.id. 3Iarkings pruinose, lines distinct, entire or interrupted, those 

 converging to the processes most curved near their outer ends, the 

 others radiating straight, or gently curved towards the processes, \\ ith 

 narrow hyaline interspaces, sometimes more crowded around border ; 

 non-apiculate. Processes 2 or 3. round, 0*0125 to 0*0l!5 mm. broad, 

 their cucumference with slight irregularities. — Ealfs in Pritch. Inf., 

 p. 8-15. Grev. Trans. Mic. Soc. Lond":,18G3, p. 48, pi. iii. fig. 13. H. L. 

 Smith, Sp. Diat. Typ. Sup. No. 706. 



In H. L. Smith's specimens the bevelled edge described by Bailey, 

 but questioned by Greville, is quite distinct. The form described as 

 perhaps A. pruinosus var. by Schmidt (Atl., pi. cxxv. fig. 8) may 

 come here. 



Habitat : Charleston Harbour (Kitton ! ) ; Bahia (Kitton ! 

 Hardman ! Deby !); Pensacola, Florida (H. L. Smith!) ; Nottingham, 

 U.S., and Port Elizabeth (Hardman !*). 



A. acutiusculus sp, n. 



Elliptical, major axis "14 mm., about 1^ times minor. Surface 

 rising steeply from central space to processes, the intervening areas 

 flat at centre and sloping gently at border. Colour dark grey. 

 Central space circular, • 02 mm. broad. Markings granular, irregular, 

 the lines converging to the processes prominent, irregular, closely 

 placed, those radiating from the central space on the intervening areas 

 straight, indistinct in their inner half, more evident and crowded 

 around the border, interspaces hyaline. Processes 2, elliptical, 0*0175 

 mm. broad, reaching the border. — PI. XIV. fig. 1. 



Habitat : Santa Barbara deposit (Hardman !) ; San Pedro (Grove !) 



§ 9. Stellati. 



Surface divided into zones. Markings costate, distant, arranged 

 in a star-shaped manner around central space on the innermost zone. 

 Border formed by a single band of granules in contact with one 

 another. 



A. stelliger Petit., Fonds de la mer, 1877, p. 37, pi. v. fig. 35. 



Elliptical, major axis about • 04 mm., 1 \ times minor. Surface 

 with 3 distinct areas : the central subeircular, extending to about 1/4 

 of radius, the median extending almost to the semi-radius, sharply 

 defined, the external widest. Central space minute, circular. Markings 

 on the central area, 5 distinct costate rays in the form of a star, on 

 the median area the rays irregular, straight or slightly bent, on the 



* In the Collection of Mr. A. de Souza Guimaraeus. 



