ij 
95 
Gen. Rhodochorton, Nag. 
R. membranaceum, Magn. 
Fig.: Rosenvinge (1909), Pt. III, p. 393. 
District : Port St. Mary. 
Notes: Recorded by R. J. Harvey-Gibson. No data available. 
R. Rothiit, Nag. Common. 
Fig.: Harvey III, 274 [as Callithamnion Rothii}. 
District: Port Erin; Port St. Mary. 
Zone: H.W.O.N.T. to L.W.O.N.T. 
Occurrence: Perennial. 
Reproduction: Tetraspores in Spring. 
_ Notes: Common on rocks in crevices or in accumulations of sand 
or grit. 
R. fioridulum, Nag. 
Fig.: Harvey III, 275 {as Callithamnion floridulum}. 
District: Port Erin; Douglas Bay (Mrs. Gatty). 
Notes: No data available. 
Gen. Callithamnion, Lyngb. 
C. byssoides, Arn. Not common. 
Fig.: Harvey III, 262. 
District: Port Erin; Kirk Onchan (Brady). 
Zone: L.W.O.S.T. and below. 
Occurrence: Annual, Spring and Summer. 
Reproduction: Tetraspores from the end of February onwards. 
C. polyspermum, Ag. Frequent. (See Note 18.) 
Fig.: Harvey III, 263. Plate XVII, 64. 
District: Port Erin; Port St. Mary; Castletown; Douglas Bay 
(Mrs. Gatty). 
Zone: M.T. zone to L.W.O.N.T. 
Occurrence: Pseudo-perennial. — 
Reproduction: Tetraspores in Winter. 
C. scopulorum, Ag. Frequent. 
ies? Plate XVI, 57. Plate XVII, 62. 
District: Port Erin. 
Zone: H.W.O.N.T. 
Occurrence: Pseudo-perennial. 
Reproduction: Tetraspores in Winter and Spring. 
Notes: Occurs on rocks and stones near high water; very similar to 
Callithamnion polyspermum but smaller; not epiphytic. 
| C. voseum, Harv. Occasional. 
tig. : Harvey Il, 261. 
District: Port St. Mary; Douglas Bay (Talbot). 
Zone: L.W.O.N.T. to L.W.O.S.T. and below. 
Occurrence: Annual, Summer. 
Reproduction: Spermatia and tetraspores in Summer; cystocarpia 
in Spring. 
