Greville, on New Diatoms. 
55 
face) of the horns is very minutely punctate. Length of valve 
•0017" ; length of horns -0013. 
Triceratium. 
Triceraiium Hardmanianum, n. sp., Grev. — Large; valve 
with straight sides and subacute angles ; central space filled 
up with a somewhat hexagonal figure^ extending to the margin, 
and furnished with radiating puncta and imperfect radiating 
costse ; within this is a triangular figure, having a large spine 
in the centre surrounded by a circle of smaller ones; angles 
within, furnished with puncta and vein-like lines and indistinct 
pseudo-nodules. (Fig. 25.) 
Hab. Barbadoes deposit, Springfield estate ; extremely 
rare ; Laurence Hardman, Esq. ; Professor Hamilton L. 
Smith. 
One of the rarest and most beautiful species of the genus, 
and as such, I have the more pleasure in bestowing upon it 
the name of its finder, Laurence Hardman, Esq., of Rock 
Park, Birkenhead, to whom I am indebted for one of the 
only two specimens he has hitherto met with. From a 
drawing kindly transmitted to me by my eminent correspon- 
dent. Professor Hamilton L. Smith, of Kenyon College, 
Gambler, Ohio, it is evident that he also must be associated 
in the discovery. Like another diatom of the present series, 
Forodiscus splendidm, it has only occurred in samples of Bar- 
badoes deposit brought from Springfield estate. The sculp- 
ture of the valve is exceedingly rich and varied. In the 
centre we have, enclosed in a small well-defined triangle, a 
strong spine with a circle of small ones, and a few inter- 
mingled puncta. This triangle is surrounded by a broad, 
somewhat hexagonal band, filling up so much of the body of 
the diatom as nearly to cut off the angles. From the outer 
margin of this band a number of costse of different lengths 
are given off to the interior, none of which reach the inner 
boundary. The angles are filled with roundish cellules 
rather unequal in size, and faint, anastomosing, vein-like lines. 
Distance between the angles '0040". 
Triceratimn pawperculum, n. sp., Grev. — Minute ; valve 
with straight sides and rounded angles ; surface with a few 
remote scattered puncta ; margin with short broad striae ; 
angles cut off by a transverse line, forming pseudo- nodules 
very minutely punctate. (Fig. 26.) 
Hah. Barbadoes deposit, Cambridge estate ; in slides com- 
municated by C. Johnson, Esq. 
A small portion only of the angle is cut off by the trans- 
