319 
23rd March, 1871. 
Dr. John Barker showed, in use, his new paraboloid, with 
lateral stop, on immersion principle, by which he succeeds in very 
effectively bringing out the extremely delicate striz of Amphi- 
pleura pellucida, and of other equally difficult tests. 
Dr. Richardson exhibited a varied series of stops he had con- 
trived for use with the condenser for producing obliquity of light, 
which he had found very advantageous in bringing out the delicate 
markings on diatomaceous frustules. 
Mr. Arthur Andrews drew attention to a peculiarity in a marine 
species of Cythere, which had struck him as being noteworthy, 
consisting in the fringe of long hairs somewhat unevenly surround- 
ing the margin of the shell. Mr. Andrews would investigate 
this form more closely, and again refer to it. 
Mr. Archer exhibited some examples of the seeming encysted 
state of Syncrypta, referred to in his remarks at last meeting. 
Dr. E. Perceval Wright exhibited mounted calcareous spicules 
from the barky layer of a very pretty Gorgonoid Coral, which he had 
lately received from the Bermudas. It had been sent by the 
Honble. R. Rawson, entangled in the long arms of Asterophy- 
ton muricatum. On examination it proved to belong to a new 
genus, Callicella of Dr. J. E. Gray, who had described it from a 
specimen brought by Consul Swinhoe from Formosa. The Ber- 
muda specimens did not appear to differ from those from Formosa, 
and Dr. Wright, therefore, referred the former to the Callicella 
elegans of Gray. The branches of the coral could scarcely be 
said to be dichotomous. The bark in fresh specimens was mode- 
rately thick, and the spicules were of that rough irregular outline 
more or less characteristic of the Primnoade. The wide distri- 
bution of this apparently little-known form, and the fact that the 
spicules connect it closer to the Primnoade than to the Cal- 
ligorgonide, where it had been placed by Dr. Gray, would be 
sufficient excuse for bringing it before the Club. 
Professor Thiselton Dyer exhibited a section of the fossil 
vegetable form called Prototawxites Logani, and simultaneously a 
section of Taxus, with a view to draw attention to the struc- 
tural distinctions which seemed to indicate that the so-called 
Prototaxites was most probably rather allied to some algal form ; 
he would suggest possibly to some belonging to Codiex, such as 
Rhipozonium, than to a Gymnosperm. There was no appearance 
of “discs ;’ both longitudinal and vertical sections seemed to 
indicate that the mass was composed of a number of tubes, running 
in a nearly parallel direction, rarely bifurcating, and seemingly 
not septate or tapering, and with an intercellular medium, appa- 
rently formed of minor tubes. The principal longitudinal tubes 
appeared, on transverse section, to have a wall concentrically 
stratified. Principal Dawson, in describing the Devonian rocks of 
