RED ALG^. 171 



inaria flexicauUs, and on shells and stones, at a depth 

 of ten to forty fathoms. It has been collected on 

 the coast of Maine at a depth of seventy-five, and 

 m the Arctic seas at a depth of eighty-five fathoms. 

 It is very plentiful in Massachusetts Bay, and along 

 the whole coast northward. It is sparingly found 

 soutn of Cape Cod. It is to be looked for among 

 the masses of sea weeds rolled up by the tides along 

 our northern — especially rocky and pebbly — beaches. 

 It is scarcely ever absent from such rejectamenta 

 of the sea, for it is a perennial. It is as easily dis- 

 tinguished there, as are the leaves of the oak or 

 maple, among the fallen foliage of the forest. In 

 some of its forms, it bears no inapt resemblance to 

 the young leaf of the oak. In England, it is called 

 the oak-leaf Delesseria. In California, we have the 

 true oak-leaf form, called D. quercifolia, which is 

 not much unlike this species. 



The plant grows from three to six inches or more 

 high. It is sometimes narrow, and sometimes quite 

 broad as is the one, which i? copied for this vol- 

 ume, and represented life size, in Plate X. It is ex- 

 .tremely variable in outline, but the ia,ct that it is 

 the only red Alga which has a regularly midribbed and 

 veined frond, like the leaves of trees, removes all 

 difficulty in the way of its ready recognition, when- 



