A 'Revision of the Genus Auliscus Ehrh., &c. By J. Rattray. 893 



transverse median areas distinct, with outer ends rounded about 3/5 

 of radius from centre, slope towards border gentle. Colour pale grey, 

 darker at outer ends of transverse areas. Central space round, distinct, 

 0*01 to O'OIS mm. broad. Markings delicate striae, those converg- 

 ing to processes most evident, the others almost straight or slightly 

 convex towards processes at border; apiculi numerous, irregular, 

 most prominent at outer ends of transverse areas. Processes 2, 

 roundly elliptical, from • 025 to • 325 mm. broad. 



Girdle aspect * showing obliquely truncate processes with margin 

 slightly protuberant. Girdle hyaline, with median line parallel to its 

 edges, • 025 mm. broad in valve 0*115 mm. in diam. — Sch. Atl, 

 pi. XXX. fig. 15. 



Habitat : Peruvian guano (Firth ! Eae ! Kitton !) ; Mejillones 

 guano (Kitton !) ; Pisagua ( Weissflog ! Kitton ! *) ; Mejillones, Bolivia 

 (Firth ! Bessels ! f) ; Pabellan de Pico guano (Cleve). 



§ 14. Ketifokmes. 



A reticulum over entire surface or confined to central or peripheral 

 portions, sometimes indistinct. Markings obscure, delicate striae or 

 costse, or forming punctate interrupted strands. Interspaces hyaline. 

 Apiculi obscure or absent. 



A. textilis Sch. Atl., pi. Ixsxix. fig. 9. 



Subcircular, diam. • 095 mm. Surface sloping gently to border. 

 Central space circular, distinct, 0*015 mm. broad. Markings a deli- 

 cate reticulum with minute irregular meshes, having delicate points at 

 the angles. Border distinct, with irregular radial or somewhat oblique 

 lines. Processes circular, 0*019 mm. broad, central portion relatively 

 small, hyaline. 



Habitat : Santa Monica deposit (Schmidt). 



A. suhreticulatus. — A. pruinosus var. suhreticulata Grrun., Sch. Atl., 

 pi. Ixxxix. figs. 5, 6. 



Elliptical, major axis 0*075 to 0*13 mm., 1 J to 1^ times minor. 

 Surface flat or central portion sometimes slightly elevated, with outer 

 edge distinct and convex between processes. Colour pale grey or 

 smoky grey. Central space rounded, 0*01 to 0*0175 mm. broad, 

 distinct. ^Tarkings evident, striae converging to the processes, those 

 on intermediate areas indistinct, straight, radial, a reticulum with 

 unequal meshes well defined ; apiculi absent. Processes 2, round or 

 elliptical, * 0175 to * 0275 mm. broad, their circumference sometimes 

 rough. 



Habitat : Santa Monica deposit (Piae ! Firth ! Griffin ! Cleve !) ; 

 Crescent City, California (Weissflog ! Griffin !) ; Los Angelos (Hard- 

 man ! I). 



* Also in the Collection of Dr. GrifBn and Mr. E. Grove, 

 t In the Collection of Dr. Griffin. J In the Collection of Mr. Julien Deby. 



1888. 3 p 



