ON THE DEVELOPMENT OF LICHENOPORA VERRUCARIA. 99 
The following stages are naturally marked out by the phe- 
nomena of the development. 
Stage A.—Formation of the definitive egg (figs. 15—18). 
The entire colony in which this stage occurs measures about 
‘45 mm. in length, and about ‘25 in transverse diameter 
(between figs. 2 and 8). 
Stage B.—Formation of the follicle and suspensor (figs. 
19—22). The colony does not differ materially in size from 
those in which Stage A occurs. 
Stage C.—‘Suspensor stage” (figs. 10, 23, 24), the 
embryo being supported by a functional polypide. Colony in 
the condition of figs. 3 and4; usually about ‘50—-60 mm. long, 
and about °35—'55 mm. broad. 
Stage D.—The polypide has degenerated, and the embryo 
is supported by a brown body found near the distal end of the 
fertile zocecium (figs. 27, 28). Colony as in Stage C. 
Stage E.—Disappearance of the “ suspensor”’ and enlarge- 
ment of the embryo (figs. 29, 30). 
Stage F.—Commencement of embryonic fission (figs. 31— 
35). Diameter of colony about ‘60—:80 mm. 
Stage G.—Fully formed ovicell (figs. 7, 11, 12). 
The measurements given here and elsewhere, so far as they 
refer to sections, must be taken as approximate. The plane 
of the sections may not be such as to permit of a satisfactory 
measurement being taken at all, while in the case of an 
oblique series the whole length or breadth of a colony may 
not be seen in any one section ; and the necessity of estimating 
the length obviously introduces a source of error. The delicate 
calcareous lamina which forms the edge of the entire colony 
is usually not distinct in sections. Lastly, there is consider- 
able variation in the size of the colony and in the time at 
which development commences. 
In spite of these drawbacks, I believe that it will be useful 
to record the measurements of the colony, wherever possible, 
as a guide to future investigators. The measurements given 
in the sequel refer in all cases, unless the contrary is stated, 
to the sections, and not to the colony before decalcification, 
