608 Proceedings of Royal Society of Edinburgh. [sess. 
C. japonicus, Cleve,? recorded in Habirshaw’s Cat. Diat.. 2nd 
ed., § Cestodiscus , was most probably distinct. 
C. tenerrimus. Ehrb., Abh. Ber. Ah , 1872, p. 208. — Specimens 
were procured by Capt. Gerder in the White Sea, in 1857. 
C. wallichianus , Grnn. Cleve and Moll., Diat., No. 183, — 
Specimens procured from the Southern Ocean. 
C. coinplexus , Stodder, has been recorded in Habirsh., Cat. 
Diat., § Coscinodiscus. The photograph there referred to has not 
been published. 
C. Febigerii , H. L. Sm., is also recorded in Habirsh., Cat. Diat., 
§ Coscinodiscus, where it is stated with some doubt to be a var. of 
C. excavatus .* 
C. Challengeri, Janisch f (“ fragments not rare ”) ; C. maryland- 
icus, Grun.; and C. pumilus, Grun., are names that have been 
applied to forms said to occur in Cleve and Moll., Diat., No. 216, 
which is a preparation from the Nottingham deposit, U.S. 
A very distinct and interesting species has recently been dis- 
covered by Mr Edmund Grove, and named by him Coscinodiscus 
lacunosus, of which the following is a diagnosis : — Diam. *0575 mm. 
Surface and central portion extending to about J of radius, slightly 
elevated, the elevation at its outer edge passing into a faint depres- 
sion, which in turn rises gently to the marginal zone. Central 
space distinct, angular with a single well-marked circular granule, 
elsewhere hyaline. Markings round, granular, closely disposed on 
the central elevation and near border, least crowded on the de- 
pressed zone, subequal 5J to 6 in *01 mm ; rows radial, straight, at 
subregular intervals between the rows large hyaline interspaces 
almost as conspicuous as the intervening rows ; apiculi minute but 
distinct, inserted at inner edge of border opposite the outer ends of 
the hyaline areas. Border with inner edge well defined, '002 jnm. 
wide; striae delicate but distinct, 8 to 10 in '01 mm. 
Habitat. — Totara, New Zealand fossil (Grove !). 
* With respect to C. Febigerii , Mr E. Grove informs me that there is no 
doubt as to its identity with C. excavatus , and that Prof. W. H. Smith him- 
self has admitted this. 
t According to^ Mr Grove, C. Challenger F is probably identical with C. 
Gazellae. 
