1888 - 89 .] Mr John Rattray on the Genus Coscinodiscus. 649 
compartments reaching about of radius inwards, their inner ends 
transversely truncate, or slightly convex towards the centre, their 
adjacent sides formed hy a large cuneate areola, distinctly protrud- 
ing by an inwardly convex inner end into the interradial space and 
attenuating towards the border, elsewhere the areolae evident, 
decreasing rapidly outwards from 4 to 8 in *01 mm.; the intervals 
obsolete. Border narrow, indistinct. 
Habitat. — Barbados deposit (Greville ! T. G. Rylands, de 
Brebisson, Grove !) ; Springfield deposit, Barbados (Hardman !). 
A. tenerrima ,* sp. n. — Diam.? Central areolate area absent. 
Markings : rays 4 to 7, straight ; the compartments reaching from 
§ to \ of radius inwards, their inner ends concave towards centre 
or transversely truncate ; a single hand of large areolae bounding the 
inner ends, outside of this a single large lanceolate areola extending 
close to the border hounding the interval; elsewhere the areolae 
small, evident, in distinct radial and less manifest suhregular 
concentric zones ; intervals extending to border of uniform width. — 
(PL III. figs. 18, 20.) 
Habitat . — ? 
A. affinis. Grev., Trans. Micr. Soc. Lorid., 1862, p. 45, pi. vii. 
figs. 7-9. — Diam. ’0675 to ’1175 mm. Colour pale grey, the rays 
more opaque. Central areolate area from *0125 to *0175 mm. 
broad, sometimes absent ; a small central space rare. Markings on 
central portion 2 in *01 mm., hyaline; rays straight or slightly 
flexuous towards the inner ends ; the compartments reaching from 
* This species is established on two specimens occurring in a photograph 
now in the possession of Mr Julien Deby, the history of which is given in a 
letter addressed to him by Herr E. Weissflog dated 27th July 1878. Herr 
Weissflog says : — “ I have received a letter from Mr F. Habirshaw of New 
York, in which he says — ‘The late John E. Gavit . . . engraved the fine 
plate in Bailey’s “New Species,” &c. (Smith’s Contrib.). He also some years 
ago made a plate which suddenly disappeared — neither plate nor impressions 
could be found. In overhauling the effects of Judge Johnson (of Asterodiscus 
in Silliman's J our. ) two impressions were found, and it is believed that they 
are the only two extant. A few days since we photographed the one sent us, 
and we hope that you will be pleased with the result. If there are more 
wanted, I would like MM. Deby and Delogne to have copies.’ Herewith you 
will find two proofs, and you will oblige much by remitting one to M. Delogne.” 
Nothing further is known of the specimens. They seem, however, to come 
from the Barbados deposit. 
