1888 - 89 .] Mr John Rattray on the Genus Ooscinodiscus. 561 
deposit (Kinker !) ; Mejillones (Cleve ! O’Meara !) ; Santa Monica 
(Schmidt, Grove ! Kinker !) ; Nottingham deposit, Md. (Greville ; 
Cleve and Moller !) ; “Maryland” (O’Meara!); Richmond tunnel 
(O’Meara!); Richmond, Ya. (Cleveand Moller!); Bermuda tripoli 
(Greville!); “Barbados” (Johnson!); Cambridge deposit, Bar- 
bados (Johnson!) ; Holland’s Cliff (Cleve !) ; Marstrand (Kinker !). 
Yar. morsiana. Grun., ibid., 1884, p. 77. — Diam. *23 mm. 
Surface slightly depressed towards the centre, the highest zone 
about | of radius from centre. Central rosette distinct. Markings 
robust, increasing from the centre for § of radius, thence diminish- 
ing to the border ; towards centre 3, on highest zone 2 to 2 \, in ‘01 
mm.« — Sch., Atl., pi. lxiii. fig. 9 (no name) ; C. asteromphalus, 
Ehrb., ( fide Grun., ibid., p. 77); Sell., Atl., pi. lx. fig. 7 ; Cestodiscus 
radiatus, Ehrb.; Van Heurck, Syn. Diat. Belg., pi. cxxix. fig. 5. 
Distinguished by the wider zone at the border, upon which the 
markings decrease. 
Habitat. — Mors deposit (Schmidt, Cleve !). 
Yar. subspinosa. Grun., ibid., 1884, p. 67. — Diam. *1665 mm. 
Central rosette small, often with a small central space. Markings 
more delicate, 4 to 5, at the border 7 to 8 in -01 mm. Apiculi 
minute, numerous, at subregular intervals, inserted close to border. 
— Sch., Atl., pi. lxiii. fig. 4 (no name). 
Habitat. — Mejillones guano (Grunow, Grove, O’Meara!) ; Ichaboe 
guano (Schmidt). 
Yar. tenui-striata. Grun., ibid., 1884, p. 77. — Diam. *14 to *15 
mm. Surface very convex on outer portion. Markings at the 
centre 5, towards the border 6 or 7, in ’01 mm., non-apiculate. 
A smaller form with smaller markings, 7 to 10 in *01 mm., 
occurs in the Caspian. 
Habitat. — Campeachy Bay (Grunow). 
Yar. stelliger. Sch., Atl., pi. lxiii. fig. 8 (no name). — Diam. 
2 mm. Central rosette distinct. Markings subequal to, but more 
irregular than those of the type ; towards the border larger, and 
forming a circlet of distinct rosettes, placed at regular intervals 
about i of radius from the border. 
Habitat . — Java (Schmidt). 
vol. xvi. 29/10/89 2 n 
