Greville^ on Aster olampr(B. 
45 
as hitherto observed,, has the curve of the segments beauti- 
fully symmetrical. Specimens from the South Naparima^ 
Trinidad deposit (having seven rays and a diameter of "0052"), 
agree in this respect with typical examples. But such is not 
the case with those from Barbadoes. In these^ the inner 
margin of the segments is by no means regular. It is often 
more or less truncate^ sometimes sharply so on one side^ 
while the other side of the same segment is rounded ; in 
fact^ I have not seen a single valve with regularly curved 
segments. Notwithstanding this circumstance, there can 
be no doubt, I think, that fig. 3 is really A. Mary Ian- 
dica. There is a much greater deviation from the type in 
fig. 2 ; the segments being actually truncate, and yet one of 
the sides is sometimes so rounded as to indicate a return to 
the normal outline. The valve represented at fig. 1 is very 
singular. The rays are broad and obese, and the segments 
have their curve so much flattened as to be partially truncate. 
It is very rare, three specimens only having come under 
observation. 
2. Asterolampra decora, n. sp., Grev. — Segments short, 
having their inner margin truncate, and composed of oblong, 
punctiform cellules, the lateral angles not projecting; umbi- 
licus (always?) cellulate. Diameter -0023" to -0030". (Figs. 
4—6.) 
Barbadoes deposit ; T. G. Bylands, E. K. G. 
Notwithstanding the punctiform character of the cellules 
of the inner margin of the segments, this species comes near 
to some of the varieties of A. vulgaris. The marginal cellules 
vary somewhat in size and in being more or less oblong, but 
still are very unlike the large oblong cellules of the diatom 
just mentioned, and the lateral ones do not project beyond 
the rest. The number of rays is most uncertain. I have 
examined a large suite of specimens, and in twenty-five, of 
which I have taken notes, the number varied from five to 
fourteen, and that of the umbilical cellules is equally uncertain. 
In one specimen only were the latter wholly absent, so that 
their presence may be fairly assumed as generally charac- 
teristic. The puncta of the segments are occasionally dis- 
posed in radiating lines. 
3. Asterolampra affinis, n. sp., Grev. — Segments elon- 
gated, minutely punctate, sharply truncate ; umbilicus simple 
or cellulate ; umbilical lines undivided. Diameter '0024" to 
•0050". (Figs. 7—9.) 
Hab. Barbadoes deposit. 
A well-marked species, which cannot be confounded with 
any other in the Barbadoes deposit. To A. Grevillii, how- 
ever, it bears a great general resemblance ; but differs in the 
