THE MARINE ALGiE OF NEW ENGLAND. 17 



locular and plurilocular sporangia are borne at the base of the peripheral 

 filaments. In Elachistea there are also paraphyses. 



Chordaeieje. — In this family the branching frond is filamentous, 

 and consists of an axis of longitudinal filaments and a peripheral series 

 of short filaments, which are given off at right angles to the axis. The 

 sporangia are found amongst the peripheral filaments, the unilocular are 

 ovoidal, and the plurilocular arise from the metamorphosis of the cells 

 at the outer extremity of the peripheral filaments. 



Asperococceje. — The fronds of this family are the counterparts of 

 those in the Scytosiphonece, but the sporangia, instead of being superficial, 

 are external and do not cover the whole surface, but are found in spots. 

 The spots contain paraphyses and spherical unilocular sporangia. 



Balfseb^. — In this family, composed of very few species, the frond 

 is in the form of a crust, resembling a lichen. The fruit is found on the 

 surface in spots, composed of paraphyses and unicellular sporangia. 



Sporochne^. — Here the frond is a solid branching filament and the 

 fruit is found in spots on the surface. Each spot consists of a number 

 of paraphyses, at the base of which are either oval unilocular sporangia 

 or plurilocular sporangia in the form of short filaments, resembling the 

 sporangia of Phyllitis. 



Laminarie^. — The family which includes the devil's aprons and sea- 

 colander of our coast. The fruit either forms long patches or more or 

 less irregular spots along the center of the frond. Unicellular sporangia 

 only are known. The sporangia are separated from one another by pe- 

 culiar-shaped unicellular paraphyses, which are expanded at the top so 

 as to cover the sporangia. 



Oosporeje. — In the order Zoospores the sexual reproduction consists 

 in the direct union of two zoospores, which form a zygospore. The two 

 conjugating zoospores, or gameten if we adopt De Bary's nomenclature, 

 are alike in structure, and it is impossible to say which is male and 

 which is female. In the Gutlsriece, of which no representative has as 

 yet been found on our coast, we have alg® resembling the Phceosporece 

 in habit, but differing from them in that their reproduction is of a higher 

 grade. The Cutleriw have both zoospores and antherozoids, or proper 

 male organs. The zoospores are large, and are born singly in cells, 

 which are united in eights into an oblong body. The antheridia borne 

 on distinct individuals are also oblong in shape, but, instead of being 

 divided into eight cells, they are formed of a much larger number of 

 small cells, in each one of which an antherozoid is produced. The an- 

 therozoids are small oval bodies, almost colorless, and provided with 

 two lateral cilia. In Cutleria collaris Eeinke found that the zoospores 

 after swimming about for some time, lost their cilia and came to rest. 

 While at rest the antherozoids approached them, and he considered that 

 the sexual union then took place. Here, then, we find a clear distinc- 

 tion of the sexes such as is nowhere found in the Zoospores, and it is 

 but a step higher to the Oospores, in which we have a distinct male 

 8. Mis, 59 2 



