239 
It is uncertain if Sluder’s Halomitra tiara is a synonym of 
H. tiara Agassiz, described by Verri 11 (1864). According to Ver¬ 
ri 11 the theca in H. tiara is solid, whilst Studer States that the 
theca in his specimens has many irregularly scattered pores. There- 
fore I have retained the name H. philippinensis for the species in 
which the three above-mentioned species of Studer are united. 
I cannot decide if Studer is right in placing M.-Edwards 
and Haime’s Halomitra pilens in the synonymy of his H. tiara. 
There is much evidence that H. pilens Dana is quite different from 
H. pilens M.-E. and H., and again H. pilens Studer may differ from 
both of the other species of the same name. But I have not 
sufficient material for a comparative study of these forms. 
The specimens in the Amsterdam and the Leyden Museum 
referred by van der Horst (1921) to H. pilens and H. tiara 
belong to the same species as those in my material. In every 
specimen the costal spines possess in their apical part minute 
granulations or small ramifications. H. lonwinae van der Horst 
is based on regenerated specimens of the same species (cf. below). 
The greater part of my material of this species consists of 
regenerated fragments, only in eight specimens the central calicle 
is yet present. This latter is larger than the other ones and has 
distinctly radially placed septa. The youngest specimen is an antho- 
cyathus which has but recently detached from its stalk. Its lower 
surface has a distinet scar of about the same size as that in spe¬ 
cimens of Fnngia (fig. 98). At the upper surface there are besides 
the large central calicle three well-developed secondary calicles and 
the first traces of some more of these calicles (fig. 97). In the 
parts of'the corallum where the formation of secondary calicles has 
not yet taken place the different cycles of septa can be disting- 
uished in the same manner as in Fnngia. There are seven com- 
plete cycles of septa, the pairs of septa of the higher cycles have 
fused with the marginal part of a septum of a next lower cycle. 
In older specimens the septa are divided into parts by the formation 
of the secondary calicles and the different higher cycles are no 
more to be distinguished. In this very young specimen the costal 
spines already are provided with granulations and minute rami¬ 
fications as in the larger colonies of this species. The measurements 
