l88 CALIFORNIA ACADEMY OF SCIENCES. [Proc. .3D Ser. 



determine this point if possible. The results obtained by 

 the writer therefore agree rather with those obtained by 

 Reinke and Bornet than with those of Berthold and others. 



While some species of Porfhyra are monoecious, others 

 are dioecious. In some cases fronds have been found 

 which evidently approached closely to those of a monce- 

 cious species, but which differed from it in being dioecious 

 and in exhibiting some slight differences of habit, etc. 

 Such fronds have been referred to the original species but 

 were separated from it under a form-name. 



We may distinguish two forms of monoecious fronds. In 

 the one, antheridia and sporocarps are separated in patches. 

 These patches are usually sharply defined, especially at the 

 edges of the frond, owing to the lighter color of the ripe 

 antheridia and to the more intense color of the ripe sporo- 

 carps. This arrangement is usually met with in the fronds 

 of the monostromatic species. In the other form, the 

 antheridia and sporocarps occur side by side, so that the 

 frond has a uniform color. This occurs in the distromatic 

 species, and more particularly in what the writer has found 

 convenient to designate the '■'■mmiata group," which in- 

 cludes P. ampJissima, P. miniata, P. tcmiissima and P. 

 abyssicola. 



Vegetative cells are frequently found mixed with the spo- 

 rocarps, among both monostromatic and distromatic species, 

 and in larger or smaller patches. While the distromatic spe- 

 cies show this constantly, the monostromatic species often 

 fail to show these vegetative cells among the sporocarps. 

 Hardly ever has the author found any vegetative cells 

 mixed in with the antheridia of the monostromatic species. 



Among the sporocarps there appear frequently bodies 

 which by various authors have been called monospores. 

 They seem to be formed by the arrest of division in one of 

 the segments of the sporocarp or by one of the vegetative 

 cells lying among the sporocarps. What differentiates them 

 from the vegetative cell proper is a greater thickness of the 

 cell-wall and a larger amount of protoplasm. The chromato- 

 phore may be seen lying in or near the center of the cell. 



