A 'Revision of the Genus Auliscus Ehrb., dte. By J. Batiray. 891 



A. siibJsevis Grun. MS. 



Irregularly elliptical, major axis 0*04.5 mm., about lj\ times 

 minor. Surface almost flat, a dark indistinct band between processes 

 and close to border, slope at border gentle. Colour pale grey. 

 Central space round, about 0*0025 mm. broad, indistmct. Markings 

 punctate, minute, strise just visible on central side of processes. 

 Processes 2, plano-convex, or outer side protuberant, • 01 mm. 

 broad.— PI. XII. fig. 7. 



Habitat : Moron deposit (Weissflog !) 



A. lueiclus sp. n., Scb. Atl, pi. xxxi. figs. 10, 12. 



Elliptical, major axis 0-15 mm., 11 times minor. Surface with 

 central portion slightly elevated, its outer edge faint, convex out- 

 wards, at about 2/3 of semi-minor axis from central space and passing 

 round the outer side of the processes. Colour hyaline, central space 

 round, indistinct. I\Iarkings obscure, a few delicate striae converging 

 to the processes somewhat more evident. Processes 2, round, • 02 mm. 

 broad, placed near middle of semi-major axis, their circumference 

 distinct, central portion punctate. 



Habitat : Gulf of Carpentaria (Weissflog ! Grundler). 



A. ovalis Arnott in Pritch. Inf., p. 846. 



Elliptical, sometimes more convex on one side than on the other, 

 or oval, major axis • 08 to • 125 mm., about 1^ to If times minor. 

 Surface rising slightly from the centre to the processes, transverse 

 median areas extending to about 4/5 of radius, with outer ends 

 rounded, sometimes indistinct and closer to border, outside of this slope 

 to border gentle. Colour pale grey. Central space roundly elliptical, 

 from • 008 to '0125 mm. broad. Markings delicate, closely placed 

 striae, straight in direction of axis of transverse areas, sigmoid about 

 sides of these areas, the peripheral curves convex towards the processes ; 

 apicuh few between central space and processes, and on transverse 

 median areas, chiefly at outer ends of latter, sometimes absent. 

 Processes 2, elliptical or obtusely triangular, about • 0225 mm. broad. 

 — Grev. Trans. Mic. Soc. Lond., 1863, p. 47, pi. iii. fig. 12 ; Sch. Atl., 

 pi. XXX. figs. 16, 17, pi. cxxv. fig. 3; H. L. Smith, Sp. Diat. Typ. 

 No. 55. 



Some Oamaru valves have the strise converging to the processes 

 specially well defined. 



Habitat : Iquique (Hardman !) ; Pisagua, Peru (H. L. Smith ! 

 Weissflog !) ; Peruvian guano (Griffin ! Grove) ; Islay, Peru (Griffin !) 

 Algoa Bay guano (Greville !) ; South African guano (Greville !) 

 Japan oysters (Eae !) ; Cape of Good Hope (Macrae ! Weissflog !) 

 Oamaru deposit (Grove !) ; Santa Monica deposit (Kinker !). 



