
MARINE AQUARIA 
temperate and tropical genera. Those of the Atlantic and Pacific oceans 
are similar, but for the purpose of this volume the Middle Atlantic coast 
species only will be described. 
Cape Cod is accepted as the dividing line, as north and south of it a 
markedly different marine flora exists, because the great arctic and equa- 
torial currents maintain different temperatures of the water; and though 
the more common seaweeds may be found in both sections, those to the 
north are essentially arctic and those to the south temperate zone species. 
About a third of the species of each section do not extend very far into 
the other. The common forms here mentioned occur from New England 
to the Carolinas and some still further south. 
Green Marine Atc#. Chlorospermeze have the widest range, 
and those tide-mark forms which flourish in full light and where freshwater 
reaches them at some stages of the tide, or which survive when laid bare 
by the receding tides, are the hardiest and will thrive best in the marine 
aquarium. Of these Green Algez the most generally distributed species 
are: 
Ulva lactuca, (Linn.) or Sea Lettuce, Oyster Green, has pale yellow- 
ish-green 6 to 8 inches long and 4 inches wide, thin, membranous fronds 
with crisped edges, which consist of a single layer of cellules. Quite 
generally distributed on the Atlantic coast between tide-marks and in 
deeper water, usually attached to all kinds of objects in the water. 
Ulva latissima(Linn.) or Green Laver, Heavy Sea Lettuce, has dark 
bluish-green very much broader variable fronds, which may attain a length 
of 24 to 36 inches and a width of 12 to 20 inches. The fronds are thin, 
soft and glossy, of irregular outline with waved and ragged edges. It 
grows attached below low-tide marks and is common everywhere. 
Purpyra vulgaris (Ag.) or Purple Laver, Purple Weed, is variable in 
color and may have blackish-green, purple or brown, with thin, satiny, 
ribbon-like fronds, elegantly waved, crisped and puckered on the edges. 
The fronds are also variable in form, sometimes two inches broad in the 
centre and tapering to both ends, or a broad membrane ten inches across. 
Common in shallower water everywhere, but grows to largest size in Call- 
fornia. 
Enteromorpha intestinalis (Link.) or Gut Weed, has simple unbranched 
fronds 6 to ro inches high and % inch wide, slender at the bottom but 
of the same width above. It is often inflated with air bubbles and then 
assumes the intestinal appearance indicated by the name. The color is 
light green, often yellow or white at the top. Grows in tide-pools and 
shallow water along the Middle Atlantic coast. 
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