Ulva:
Ulva – Latin for “Marsh Plant”-is very tolerant of areas of low salinity, so it is commonly found around fresh water streams and springs on our beaches.  There are many different species of Ulva some are long and thin, wide and short, frilly, ribbon like and even tubular, but all blades are two cells thick and will usually not be more then 1m long.

Hollow tube - Ulva intestinalis

Sea lettuce - Ulva

Narow and Wide Ribon - Ulva linza

Acrosiphonia:
Acrosiphonia – Greek for "tube-topped" – is commonly know as green rope and can reach 40cm in length.  If you look closely at the fine hair-like branches of Acrosiphonia, you will find the ends curl like hooks. This causes the branches to tangle and makes this green algae resemble frayed rope.  Acrosiphonia can be found from Alaska to California in mid to low intertidal areas.