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. acideatum, 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. productum, 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 graimles 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. labyrinthaum, 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 Ijnes finely punctate. Distance between 

 the angles -0023". 



T. blanditum, Grev. — Sides of valve (in my specimen 

 four-angled) deeply concave ; angles sub-hemispherical ; 

 centre Avith a small blank space ; granules conspicuous, sub- 

 remote, equal, forming straight, equidistant, parallel lines, 1 1 

 in •OOl". Distance between the angles "0020". 



