iy; 
P. linearis, Grev. Frequent. 
Fig.: Harvey IV, 344 [as P. vulgaris], 
District: Port Erin; Port St. Mary; Castletown; Pooyllvaaish ; 
Douglas Bay (Talbot). 
Zone: L.W.O.N.1T..to M.T. zone. 
Occurrence: Pseudo-perennial. 
Reproduction: January and February. 
Notes: Common in winter; appears to be the winter form of Porphyra 
umbilicalis, Kutz, var. laciniata, J. Ag. - 
P. umbilicalis, Kutz, var. laciniata, J. Ag. Common. 
Fig.: Harvey IV, 343 [as P. laciniata]. 
District: In all districts. 
fone: H.W.O.5.1. to H.W.O:N.T. 
Occurrence: Pseudo-perennial. 
Reproduction: Tetrasporangia in Spring. 
Notes: Common in Spring and early Summer; can withstand con- 
siderable exposure but is frequently destroyed in Summer 
when sunny calm weather prevails. Forms a conspicuous 
zone on smooth rock surfaces usually forming a closed 
society. 
Sub-Order. EUFLORIDEAE. 
Fam. HELMINTHOCLADIACEAE. 
Gen. Erythrocladia, Rosenv. | 
E. subintegra, Rosenv. Rare. (See note 11.) 
Fig.: Rosenvinge I (1909), p. 74. 
District: Port Erin. 
Zone: Dredged in deep water. 
Occurrence: Sporadic. 
Reproduction : Monospores in March. 
Notes: On Polysiphonia spinulosa, var. major (on Desmarestia 
aculeata). 
Gen. Colaconema, Batt. 
C. veticulatum, Batt. Very rare. (See note 12, p. 114.) 
Bie: Plate XIV, 45.- 
District : Port St. Mary. 
Zone: M.T. 
Occurrence: Occasional. 
Reproduction: April. 
Notes : Endophytic in the walls of young sporelings of an undetermined 
species of Cladophora. 
Gen. Acrochaetium, Nag. 
A. emergens, Rosen. (= C. emergens, Rosenvinge.) (See note 14, 
p- 125) Rare: 
Fig.: Rosenvinge (1909), part I, p. 128. 
District : Port Erin. 
Zone: Dredged in deep water. 
Occurrence: Sporadic. 
Reproduction : Monospores in May. 
Notes: On Polysiphonia spinulosa, var. major (on Desmarestia aculeata). 
