402 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Liehenopora verrucaria in all stages of development enabled him, not 
only to confirm the main fact of the occurrence of embryonic fission, but 
to discover certain remarkable phenomena in the life-history of that 
species. It may be pointed out that it would not be easy to find two 
genera of Cyclostomata which are more unlike than these two. It 
follows, therefore, that the occurrence of the same mode of development 
in the two forms may be taken as a good reason for believing that we 
are really dealing with a process which is normal and characteristic of 
the group. 
One very striking fact which the author has succeeded in estab- 
lishing is the restriction of the production of embryos to one or two of 
the whole colony in the normal development. This may, perhaps, be 
due to the fact that the colony in this genus is to be regarded as an 
individual of a higher order. The discoid al form and the close 
association of the zooecia have produced the result that the colony 
behaves in this respect as if it were a single individual. 
Tertiary Polyzoa of Victoria.* — Prof. Baldwin Spencer has edited 
the monograph of the tertiary Polyzoa of Victoria, which is the last 
contribution by the late P. H. Macgillivray to his favourite science. 
It was largely by this author’s efforts that the 400 species of 
recent Polyzoa now known to occur on the coasts of Victoria were 
accurately determined. In Victoria, as well as in South Australia, 
there are numerous tertiary formations containing large deposits of 
Polyzoa, the accurate determination of which, especially in relation to 
the living species, is of great interest. The most marked feature of the 
fossil species is their striking resemblance to those of the existing fauna. 
Of the species, not peculiarly Australian, which are identical with recent 
species, most are cosmopolitan. The only important innovation in 
nomenclature which the author makes in this paper is the introduction 
of the term “ thyrostome ” for the opening through which the tentacles 
and oral extremity of the polypide are protruded. The terms “ orifice,” 
“ oral aperture,” and “ mouth ” are inaccurate and confusing, and the 
proposed name will, no doubt, prove advantageous. 
. Arthropoda. 
a. Insecta. 
Abdominal Appendages of Insects, j — Dr. H. Heymons has studied 
the morphological characters of the various abdominal structures in 
insects. The cerci arise from appendages on the eleventh embryonic 
segment, but by the suppression of the latter become associated with the 
tenth abdominal segment. The styles are to be interpreted as vestiges 
of abdominal appendages, most marked in primitive forms, and under- 
going gradual reduction. They are homologous with cerci. On the 
other hand, the gonapophyses have no relation to apj>endages, but are 
secondary hypodermic outgrowths or proliferations. In no epoch of 
embryonic or larval life are there appendages on the segments on which 
the gonapophyses occur. 
* Trans. Roy. Soc. Victoria, iv. (1895) pp. 1-166 (22"pls.). 
t Morpliol. Jahrb., xxiv. (1896) pp. 178-204 (1 pi.). 
