105 
ChiIticrl NOTES 
1. Pyrastola stipitata. 
Individual plants of this species may grow to large 
size, reaching some inches in length. In the Port Erin 
district, however, the only plants found have been quite 
small, not more than a few cms. in length. 
2. Mikrosyphar polysiphoniae, Kuck. 
Batters’ “ List of British Marine Algae” in 1902 includes 
two species of Mikrosyphar, namely M. polysitphoniae 
and M. porphyrae, neither of which differ greatly from 
one another in organisation or in reproduction. They 
have been given specific rank on the basis of their endo- 
phytism in different host plants. In examining material 
on limpet shells collected at Port St. Mary in January 
and February, 1931, young plants of Polysiphonia urceolata 
showed a rich development of Mikrosyphar in the clear 
outer walls. At the same time thalli exactly similar to 
those of Mikrosyphar on Polysiphoma were also to be 
found in the walls of Ceramium sp. and of Callithammon 
avbuscula. The Polysiphoma, Ceramium and Calli- 
thammion plants were all growing in close contiguity 
on the same limpet and it is readily understandable that 
the Mikrosyphar plants had spread from the Polysiphonia 
to the Ceramium and Callithamnion. As the organisation 
and reproduction of the Mikrosyphar plants appeared to 
be exactly similar in all three cases it is proposed to 
regard them all three as specimens of Mzkrosyphar 
polysiphomae and not to make two new species M. ceramiae 
and M. callithammae. 
3. Asperococcus fistulosus, Hook. 
(= A. echinatus, Grev.) 
In Port Erin and on the neighbouring coast of Port 
St. Mary and Castletown, two forms of Asferococcus 
fistulosus are to be found. These form-variations present 
