44 THE VOYAGE OF H.M.S. CHALLENGER. 
Family I. PLestoFuNGID&. 
The family Plesiofungide has been founded by Professor Duncan to include many 
forms which modern investigation has shown to be more or less transitional between the 
Aporosa and the Fungida. As characterised by the presence of endothecal dissepiments 
as well as of synapticulee, it includes many of the genera which have been referred to 
the Lophoseride, as for instance, Tichoseris (in the preliminary notice of which no 
dissepiments were described), Pavonia (= Lophoseris, Edw. and H.) in the thick and 
more massive species of which true dissepiments are well developed and were described by 
Verrill,’ and Agaricia. In many genera which are closely related to the foregoing, and in 
which generally the species are thin and explanate, no dissepiments have been described ; 
but observations are wanting on many of the forms. 
Family I]. CycLosrripé. 
The family Cycloseridee [= Lophoseridz (pars), Duncan] includes those Fungida in 
which the wall is solid, and neither perforated nor echinulate, and in which there are no 
dissepiments. The family name is taken from the most typical genus of the group, 
Cycloseris, and is thus directly comparable to the family name Fungide, which has been 
derived from the typical genus Fungia. As the genera Pavonia (=Lophoseris, Edw. 
and H.) and Agaricia now take their place among the Plesiofungide, the terms 
Pavonidze, Lophoseride, and Agaricidee are not available for this family. 
Family III. Funem. 
It is interesting to observe that though in the adult forms of the most typical genus 
of this family the wall is perforated, yet in the young stages it is frequently almost 
solid and imperforate. 
Section IL MADREPORARIA PERFORATA. 
This section is taken as defined by Professor Duncan.’ It includes three families, 
all of which are represented in the collection. 
Family I. EupsamMip&. 
Il. Mapreporip®. 
" III. Porrrmz. 
Following Mr. 8. O. Ridley,’ I have placed the genera Montipora and Anacropora in 
the family Madreporide. It must be acknowledged, however, that the families 
Poritidee and Madreporidee are separated by but slight characters. 
1 Trans. Connect. Acad., vol. i. p. 542. ? Revision, p. 172. 3 Ann. and Mag. Nat. Hist., ser. 5, vol. xiii. p. 278. 
