Greville, on Neiv Diatoms. 
45 
The following new species of Triceratium have also been 
discovered in the Barbadoes deposit^ and will be figured and 
more fully described in a future number. 
T. aculeatwn, Grev. — Sides of valve gently and evenly 
concave; angles somewhat obtuse, with a decided pseudo- 
nodule; granules irregularly radiant; centre convex, with 
three spines. Distance between the angles -0022". 
T. cornutum, Grev. — Valve (in my specimen four- angled) 
with straight sides, and sharp angles furnished with strong 
horn-like processes ; surface minutely granulose in radiating 
lines; centre with three spines. Distance between the 
angles -0015". 
T. producturriy Grev. — Valve punctate; angles produced, 
capitate; centre divided into compartments by radiating, 
vein-like lines. Distance between the angles '0027". 
T. inconspicuum, Grev. — Minute, sparsely punctate ; valves 
(in my specimens four- angled) with the angles semicircular, 
separated from the centre by a transverse line ; centre bordered 
with a row of puncta. Distance between the angles '0005 '. 
T. delicatum, Grev. — Minute ; valve with slightly concave 
sides and broadly rounded angles, filled up with transverse 
rows of fine puncta; centre containing a pale, obtusely tri- 
angular band, within which is a triangular spot bordered 
with puncta. Distance between the angles •0012". 
T. ornatum, Grev. — Valve with rounded angles and convex 
sides ; conspicuous pearly granules sparingly scattered in the 
semi-blank central space, and forming a broad marginal band 
of radiating lines, Avhich are 7 in -001''. Distance between the 
angles -0024". 
T. labyrinthceum, Grev. — Valve with rounded angles and 
slightly convex sides ; the centre occupied with a network of 
widely anastomosing, vein-like lines, from the boundary of which 
short lines are given off towards the margin ; spaces enclosed 
by the anastomosing lines finely punctate. Distance between 
the angles -0023". 
T. blanditum, Grev. — Sides of valve (in my specimen 
four-angled) deeply concave ; angles sub-hemispherical ; 
centre with a small blank space ; granules conspicuous, sub- 
remote, equal, forming straight, equidistant, parallel lines, 11 
in '001''. Distance between the angles -0020". 
