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Proceedings of Royal Society of Edinburgh. [sess. 
to the circlet of apiculi, thence more minute to the border ; apiculi 
more distant, forming a single circlet. — Cleve and Moll., Diat., 
No. 319. 
Habitat. — Franz Josefs Land, Kara Sea, Cape Wankarema 
(Grunow ; Cleve and Moller !). 
Yar. marina , Grun. Cleve and Moll., Eiat., No. 172. — Diam. 
*025 to *03 mm. Markings 10 in -01 mm., most evident towards 
the centre, near border 12 to 14 in *01 mm.; radial rows faint, 
secondary oblique rows more evident slightly concave outwards; 
apiculi numerous, minute, about 4 in *01 mm. 
Habitat. — Davis Straits (Cleve and Moller !). 
Yar. australiensis. C. ( lacustris , var. ?) australiensis, Grun., ibid., 
1884, p. 86, pi. iv. (D) fig. 31 a, by fig. 32. — Sometimes roundly 
elliptical. Diam. *02 to - 073 mm. Surface convex on one half of 
valve, concave on the opposite ; a short transverse central band. 
Markings punctiform, 10 to 12 in ’01 mm.; apiculi distinct, forming 
a single circlet. 
The apiculi are less crowded than in var. septentrionalis , but 
more so than in var. hyperborea. 
Habitat. — Brackish water, Australia (Grunow); Whampoa mud, 
China (Kitton !) ; Yarra Yarra, Australia (Kitton !). 
C. plicatulus, Grun., Denk. Wien. Ak ., 1884, p. 86, pi. iv. (D), 
fig. 27. — Diam. *04 mm. Central space absent. Markings small, 
rounded, granular, about 6 in *01 mm., smaller and subpunctiform 
towards the border ; interspaces hyaline, irregular, subequal to the 
zone of the processes, thence smaller to the bolder; secondary 
irregularly concentric rows distinct ; apiculi numerous, large, at 
subregular intervals of *005 to *006 mm., inserted some distance 
from the border. 
Habitat. — Monterey tripoli, Cal. (Grunow). 
C. pulclierrimus , sp. n. — Diam. *035 to ’045 mm. Surface flat. 
Central space absent. Markings rounded, granular, to 6 in 
*01 mm.; from the centre 5 to 8 narrow hyaline lines passing 
outwards to the semiradius, and terminating in funnel-shaped 
expansions ; between the latter and the centre the markings 
