36 
ZOOLOGY OF THE FAR EAST. 
Adult zooecia are flattened, oval or ovoid and not or but very slightly peduncu- 
late. Young terminal zooecia arise in the form of slender, pointed, flattened cylinders, 
which reach almost their full length and then expand fan-wise at the tip until they 
take the form of a comparatively long and narrow peduncle supporting a triangular 
or pentagonal head. The whole structure then gradually expands from in front 
backwards until the adult oval or ovoid outline is assumed. The ectocyst is hyaline 
and colourless except round the orifice ; the margins of the zooecium are not thick- 
ened but are surrounded b}' a narrow rim of flat membrane. The orificial tubercle is 
low. The orifice is surrounded on three sides by a brownish chitinous rim, which 
does not bear spines, though it is usually quadrate or subquadrate, and is broadly 
interrupted posteriorly or proximally. 
I can find no definite diagnostic characters in the polypide or musculature. 
Both are admirably displayed in stained and mounted specimens (pi. i, fig. 9). 
Type-specimens. No. 7152/7 Z.E.V., Ind. Mus. (Zool. Survey of India); in 
alcohol. 
Locality, etc. Small lake at the base of a limestone hill (Bukit Jalor) in the in- 
land state of Jalor or Yala in the Siamese province of Patani in the eastern part of 
the Malay Peninsula. The specimens, which were taken in the first week of Feb- 
ruary, 19 16, were growing on a dead palm- leaf that had fallen into the water. 
Specimens were also taken by Mr. H. C. Robinson and myself at the same place in 
1901. They met with an accident that caused them to dry up and I identified them 
provisionally as H. lacustris. 
The colony is as a rule less congested than in H. lacustris and H. cambodgiensis , 
if more luxuriant in its growth than H. moniliformis. This is mainly because lateral 
branches are sparingly, but not very sparingly, produced. The successive forms 
assumed by the young terminal zooecia are most characteristic. In the other species 
I have seen the buds often attain a considerable length as flattened C3dinders, but 
seem to assume the adult form gradually. Even in H. cambodgiensis , in which adult 
zooecia are normally pedunculate, I cannot find any state comparable to those 
marked c, d and e on fig. la, pi. ii. 
The parietal muscles are full}'- developed in this species and vary greatly in num- 
ber of fibres and in arrangement. In the zooecium figured on pi. i they consist of a 
number of imperfectly grouped or solitary fibres scattered chiefly on the outer side of 
the polypide. 
In specimens preserved in alcohol the roof of the zooecium usually collapses to 
some extent and consequently these muscles are somewhat distorted or displaced. 
The homologues of the pyramidal muscles of the orificial tubule in such genera 
as Paludicella consist of separate fibres grouped in a somewhat indefinite manner on 
each side of the orifice. It is not uncommon for them to be, as in the figure, mark- 
edly assymmetrical. 
The polypide, as I have already stated, agrees closely with that of H. lacustris, 
the general structure of which is discussed and figured in the ''Fauna." There is 
considerable variation in the proportions of the different parts of the alimentary 
