ON THE DEVELOPMENT OF LICHENOPORA VERRUCARIA. 71 
On the Development of Lichenopora 
verrucaria, Fabr. 
By 
Sidney F. Harmer, M.A., B.S8c., 
Fellow of King’s College, Cambridge ; Superintendent of the University 
Museum of Zoology. 
With Plates 7—10, and two figures in text. 
I HAVE formerly had occasion to describe certain very re- 
markable phenomena in the development of Crisia (6), and I 
then ventured to suggest that embryonic fission would be found 
to be characteristic of the whole group of Cyclostomatous 
Polyzoa. The development of Crisia being, to the best of my 
belief, without an exact parallel in the entire animal kingdom, 
it was important to test my former results by the study of some 
other Cyclostome. A chance discovery of large numbers of the 
colonies of Lichenopora verrucaria, Fabr., in all stages of 
development, enabled me not only to confirm the main fact of 
the occurrence of embryonic fission, but to discover certain 
previously unsuspected phenomena in the life-history of that 
species. An abstract of my results has been communicated to 
the Royal Society (8). 
It would not be easy to find two genera of Cyclostomata 
which are more unlike than Crisia and Lichenopora; 
and the occurrence of a fundamentally similar mode of develop- 
ment in the two forms may be taken as giving good reason to 
believe that we are really dealing with a normal characteristic 
of the group. Crisia is an erect, branching form, whose 
calcareous branches are interrupted at intervals by chitinous 
joints. Development here takes place in the interior of a 
