362 Transactions of the Society. 



Processes 6, insertion 4/19 of radius from circumference, cylindrical, 

 free ends truncate, no clear space at base. — PI. V. fig. 1. 



Habitat : Newcastle deposit, Barbadocs (Firth !). 



A. formosus Arnott, in Pritch. Inf., p. 843. — Diam. 0*21 to 

 • 325 mm. Surface almost flat at centre, rising slightly to inflations, 

 then steeply upon these, becoming flattened along their crest or 

 sloping slightly down to processes, slope to border gentle. Inflations 

 with sides convex, inner ends sharply defined. Colour lurid, pale 

 grey at centre. Central space rounded or quadrate, 1/28 to 1/30 of 

 diam. broad, punctate. Markings round or polygonal, 3 in ■ 01 mm., 

 interspaces punctate, rows in wide curves near inflations. Primary 

 rays with rows diverging on outer 2/3 of length. Border, inner side 

 with granules, outer with striae, 6 in "01 mm., 1/15 to 1/25 of radius 

 broad. Processes 4, insertion 2/5 to 4/13 of radius from circum- 

 ference, proximal portion smaller than distal, constriction shallow, wide 

 towards base, large but faint, space at base lentelliptical, punctate. — 

 Kitton, Month. Mic. Journ., vol. x. p. 6, pi. xxi. ; Sch. Atl., pi. xxxv. 

 figs. 7, 8. A. Brightwellii Ealfs, ibid., p. 843 ; A. ooliviensis Breb., 

 fide Ealfs, ibid., p. 843. 



Affinities to A. Petersii, pointed out by Ealfs, remote. First 

 found living by Capt. J. A. Perry, in harbours at Iquique, Pisagua, 

 Islay, and Callao, Peru, at 20 to 32 fms., associated with A. mar- 

 garitaceus, A. Comberi, and A. crux. 



Habitat : Bolivian guano (Greville ! Bae ! Dickie ! Norman ! 

 Cleve !) ; Peruvian guano (Browne ! Stokes !) ; Iquique (Kitton ! 

 Hardman !). 



A. infiatus Grev., Trans. Mic. Soc. Lond., 1863, p. 69, pi. iv. fig. 12. 

 —Diam. ■ 0625 to • 1375 mm. Surface flat for 1/3 to 4/9 of radius, 

 from its outer edge primary rays rising slightly to processes ; infla- 

 tions with margins distinct and outer ends semicircular. Colour pale 

 grey. Central space quadrate or irregular, 1/18 to 1/27 of diam. broad. 

 Markings round to bluntly angular, 4 in 0" 01 mm, decreasing but 

 slightly at border, rows straight, radial. Primary rays with rows in 

 contact only near central space. Border striae 10 in 0*01 mm., 1/25 

 to 1/30 of radius broad. Processes 4, rarely 5, insertion 1/3 to 1/5 

 of radius from circumference, cylindrical, attenuating near base, free 

 ends truncate, clear space at base minute, length about 3 times 

 breadth. Girdle 5/22 of diam. broad with 2 faint parallel lines, 

 height of inflations above girdle • 01 mm.— Sch. Atl., pi. xcii. fig. 14. 



Habitat : Cambridge deposit, Barbadoes (Johnson ! Greville ! 

 Hardman ! Weissflog !) ; Bridgewater, Barbadoes (Johnson !). 



Var. minor. — Diam. • 04 to • 0525 mm. Surface with central 

 portion extending to about 1/5 of radius. Markings granular, 

 minute, round, rows wider at middle of compartments than near 

 inflations. Primary rays with rows wide and separated to central 

 space. Border striae 12 to 14 in 0*01 mm. Processes 4, insertion 

 1/4 to 3/8 of radius from circumference. — PI. VII. fig. 4. 



Habitat : Barbadoes deposit (Johnson !). 



