34 Dr. MaddoX; on Photomicrography, 
my acute correspondent, Mr. J. Linton Palmer, at Hong 
Kong, first drew my attention. In some specimens he kindly 
sent me, a dozen strong spines may be .seen on a single disc, 
chiefly near the margin, but by no means confined to it, and 
so un symmetrically arranged that it is easy to see they are of 
an abnormal character. 
COCCONEIS. 
Cocconeis naviculoides, n. sp., Grev. — Valve broadly oval^ 
punctate, with a smooth, slender margin ; puncta forming a 
somewhat distant series of intersecting lines concentric with 
the extremities ; median line straight, with a linear-lanceolate 
belt of transverse striae on each side, interrupted at the 
nodule. (Fig. 24.) 
Hab, Barbadoes deposit, Cambridge estate ; in slides com- 
municated by C. Johnson, Esq. 
Very similar in the puncta, and in the beautiful curves in 
which they are disposed, to C. Barbadensin ; but the species 
is strikingly distinguished by the lines of transverse striae 
running along each side of the median line, as we see in many 
Naviculae. Length of frustule 'OOSO'^ 
Photomicrography, its Application and Results. 
By E. L. Maddox, M.D. 
(Read March 8th,- 1865.) 
The application of photomicrography possesses some 
points of such general interest to the microscopist that, at the 
request of your President, Mr. Glaisher, I have the honour 
to offer a few remarks on the subject, to accompany some of 
its results and illustrations which will be placed before you 
by Mr. How, of Foster Lane, through the medium of his 
oxy-hydrogen-gas lantern. 
The various methods adopted by the working microscopist 
in his investigations, that are not of a direct manipulatory 
character, belong chiefly to chemistry or physics. Photomi- 
crography as yet has scarcely obtained more than passing at- 
tention. The question, then, arises whether its application is 
likely to prove useful to him when engaged in the determina- 
tion of doubtful points in structure, desirous of representing 
minutiae the most delicate, the general characters of minute ob- 
jects, or small parts of larger ones, for the purpose of ordinary 
illustration, or to supply the place of the usual drawings of 
