298 



FLORA OF PLYMOUTH SOUND 



genera represented. Dredging in Cawsand Bay yields a ricli harvest 

 of interesting forms^ including in the north part of the bay — 



Stenogramme interrupta. 

 Spyridia filamentosa, tetra- 



spores, ? . 

 Dudresnaia coccinea^ tetra- 



spores, ? . 

 Halymenia ligulata. 

 Naccaria Wigghii^ fruit. 

 Spondylothamnion multifida. 

 Sarcophyllis edulis. 

 Gracilaria confervoides. 

 Phyllophora, Fastigiaria^ Rho- 



domela^ Delesseria. 

 Ceramium, Dasya, Gelidium, 



species. 

 Rhodymenia jubata and other 



species. 

 Rhodophyllis bifida. 

 Gierartina mamillosa. 



Callithamnion seirospermum and 



other species. 

 Antithamnion plumula, a and (5, 



Chantransia virgatula^ c? , $ . 

 Chylocladia parvula. 

 Arthrocladia villosa. 

 Sporochnus pedunculatus. 

 Sphacelaria cirrhosa, and pen- 



nata with propagula and 



sporangia. 

 Asperococcus compressus, with 



sporangia. 

 Scytosiphon lomentarius. 

 Chorda filum. 

 Dictyopteris polypodioides. 

 Ulva^ Enteromorpha^ Clado- 



phora. 



I found no better dredging locality for the different species of 

 Geramium than that between North Point and Pier Cove, in the 2 — 4 

 fathoms limit as indicated on the Admiralty chart. In this part and 

 towards Penlee Point Zostera beds are plentiful, affording anchorage 

 for different algae. I was pleased, too, to find a definite locality for 

 the rare (Plymouth) weed, Spyridia jilamentosa. Most of the speci- 

 mens found were tetraspore-bearing plants (a good sign so far as the 

 propagation of the species is concerned) ; c? and ? plants were also 

 found in sufficient quantities to permit one to work out in detail the 

 sexual organs and fruit formation. The dredge should be used in 

 the " If — 2| " fathoms belt, as near in to the rocks as possible, 

 immediately south of Cawsand landing beach, and on the shore side 

 of any moored boats. Cawsand Bay is not one of the easiest waters 

 in which to dredge ; on the south side the boat-anchors are very 

 troublesome, and on the north side there is a very rocky shore with 

 many submerged rocks close in. In addition to many of the species 

 of Geramium and Spyridia jilamentosa, Gallithamnion seirospermum, 

 G. gracillimum, Antithamnion cruciatum with reserve-spores, Phyllo- 

 pihora ruhens, and the more important (though by no means all) of 

 the weeds found in the north part of the bay, e. g. Halymenia ligu- 

 lata, Dictyopteris polypodioides, Gracilaria confervoides, Pylaiella 

 littoralis, Ectocarpus siliculosus, were dredged in the southern part 

 of the bay. 



