486 
Proceedings of Royal Society of Edinburgh. [sess. 
Patos Island guano (Norman !);* Nancoori; California; Sta 
Maria deposits (Grove !) ; Balearic Islands ; Pabillan di Pico guano ; 
Successful Bay, Kerguelen (Cleve !). 
Var. subsubtilis , nov. C. subtilis , Sell., Atl., pi. lvii. fig. 14. — Diana, 
"125 mm. Markings sometimes increasing slightly from the centre 
outwards or subequal; at the centre 10, at the border 8 in ’01 
mm.; rows straight, radial, fasciculate or subfasciculate towards 
the border. A narrow hyaline band adjacent to the border; 
apiculi minute, irregular, but interfasciculate, sometimes absent. 
Border strise distinct, 6 in *01 mm. 
Habited . — Peruvian guano (Schmidt); Monterey (Kinker!); 
Nancoori (Hardman !) ; f Lobos di Afuera guano (Grove !) ; marine 
deposit, Fiji Islands (Grove !); Inland Sea, Japan, H.M.S. 
Challenger (Grove !) ; Springfield deposit, Barbados (Doeg !). 
C. curvatulus, Grun. Sch., Atl., pi. lvii. fig. 33. — Diam. ’045 to 
*07 mm. Central space absent or indistinct, with numerous rounded 
granules. Markings polygonal, subequal, 6 in ’01 mm.; rows in 
gentle curves, fasciculate ; those composing each fasciculus parallel 
to that at its convex edge ; the curves on the two valves of a 
frustule in opposite directions, secondary oblique decussating rows 
obvious; apiculi absent. — Janisch, Gazelle Exped., taf. ii. fig. 7; 
taf. v. figs. 2, 3, 8; taf. vi. fig. 2 ; taf. xx. fig. 17; C. curvatulus , 
var. inermis, Grun., Denk. Wien. Ak., 1884, p. 83, pi. iv. (D), 
figs. 11, 12 ; Sch., Atl., pi. cxiii. fig. 6 ; Cleve and Moll., Diat., Nos. 
57, 154, 162, 276, 319 ; C. curvatulus, var. densius-striata (?), Sell., 
Atl., pi. lvii. fig. 35; Oclontodiscus curvatulus, Cleve, Vega Exped. 
Vetensk. Jakttag. Stockli., Bd. iii. 1885, p. 488. In H. L. Sm., 
Diat. Spec. Typ., No. 99. 
This species is sometimes confounded with the very distinct 
C. symmetricus, Grev. 
Habitat. — Los Angelos, Cal. (Cambridge !) ; Biehmond deposit 
(Rae ! Cleve and Moller !) ; Caltanisetta deposit ; Barbados deposit 
(Johnson !) ; Peruvian guano, Franz Josefs Land (Grunow) ; 
Bolivian guano (Cleve !) ; Infusorial deposit, “Algeria” (Greville !); 
* In the collection of Dr Greville. 
t In the collection of Julien Deby. 
