14 
Greville, on New Diatoms. 
luster of very minute puncta. Distance between tlie 
angles, -0033" (fig. 7). 
Hab, Barbadoes deposit^ Cambridge estate ; C. Johnson, 
Esq. 
The marginal puncta are nearly of the same size as the 
scattered ones on the surface, and are 8 in -001''. At the 
angles the very tip is cut off by a row of three or four 
puncta; and the small enclosed area crowded with much 
more minute puncta. 
Triceratum partitwn, n. sp. Grev. — Valve with slightly 
concave sides and very rounded angles, which are filled with 
minute puncta ; each angle having two transverse septa, one 
midway between the centre and the angle, the other cutting 
off the angle itself; surface dotted with remote scattered 
puncta. Distance between the angles, -0030'' (fig. 8). 
Hab. Barbadoes deposit, Cambridge estate ; C. Johnson, 
Esq. 
A beautiful and well-marked species. The angles are so 
much rounded as to appear somewhat capitate. The centre 
is marked by a small indefinite cluster of puncta, and there 
is a slight indication of a radiate direction in the other more 
remote puncta. The septa nearest the centre have a curious 
faint interruption in the middle. 
COCCONEIS. 
Cocconeis Barbadensis, n. sp., Grev. — Valve circular or 
nearly so, punctate ; median line linear, attenuated ; puncta 
minute as they form converging lines towards the extremities, 
while they are larger and form intersecting lines on each 
side; border striated. Diameter about '0032'" (fig. 10). 
Hab. Barbadoes deposit, Cambridge estate; C. Johnson, 
Esq. 
One of my specimens of this beautiful species is exactly 
circular, others nearly so. In the centre is a transversely 
oblong, blank, nodular space. The median line, taken in 
connection with the narrow, blank space on each side is linear, 
attenuated at each end. The puncta are minute towards 
the apices, considerably larger on each side, and are arranged 
in lines incurved towards the ends. Border rather narrow, 
and coarsely striated. 
