106 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



and at the time, as there were no antheridia, we hastily inferred that the spores were 

 non-sexual. It now seems probahle that the plant is the Y. litorea of Nordstedt, 1. c> 

 a dioecious species. The species was common at Wood's Holl in August, 1879, but con- 

 stantly sterile. The antheridia of V. litorea, Nordstedt, are long and cylindrical and 

 borne on a short sterile cell at the tips of the branches. The antherozoids are discharged 

 by openings at the apex and sides of the antheridium. Our plant will be easily recog- 

 ftized by its habit and the recurved branches bearing the oogonia. 



Order IV. FLORIDEA 



Algae of a red or purple color ; antheridia containing spherical, hya- 

 line antherozoids, which are without cilia ; sexual fruit or cystocarps 

 developed from a procarp, which consists of a trichogyne, at whose base 

 is a trichophore, the spores formed either from the trichophore or the ad- 

 jacent cells which compose the carpogenic system ; spores at maturity 

 either naked or inclosed in a pericarp; non-sexual reproduction by 

 tetraspores, bispores, and seirospores ; fronds filamentous, crustaceous, 

 membranaceous, or irregularly expanded, varying from gelatinous to 

 cartilaginous in substance, occasionally calcareous. Principally marine. 



The Floridece, which are the same as the Bhodospermece of Harvey, include a large 

 number of species, all of which have some shade of red, although it may be nearly 

 black on the one hand or approach shades of green on the other. In decay, however, 

 bhe color becomes orange and finally green. It is not to be inferred, however, that 

 all red algae belong to the Floridece. There are a few Cyanopliycece in which the color 

 is pink, but in these species the froud is merely an agglomeration of red cells, each of 

 which is practically a distinct individual, whereas in the Floridece the cells are organ- 

 ically united, and constitute a single plant. The structure of the frond in this order 

 varies in the different genera, and we have forms which correspond closely to the 

 fronds of the Phceosporece, as, for instance, in Nemalion we have a frond which, apart 

 from its color, is undistinguishable from that of Mesogloia, and so on. The non-sexual 

 reproduction is by tetraspores, cells which divide into four parts — rarely by bispores 

 or two-parted cells — and seirospores, or chains of oblong cells formed directly from the 

 branches. The sexual fruit, known as the cystocarp, is developed from a procarp, as 

 has already been explained. The division into suborders is founded principally on 

 the differences in the cystocarpic fruit, the full development of which is not known in 

 many cases. Differences in the fronds and tetraspores serve to mark the genera. 

 Agardh and Harvey divide the Floridece into two series — the Desmiospermece, in which 

 the spores are arranged in a definite series with regard to a placenta or common point 

 of attachment, and Gongylospermece, where the spores are heaped together without 

 order. A study of the development, however, shows that this distinction has not the 

 value which it was formerly supposed to have, and certain suborders with differently 

 arranged spores are by those who lay stress upon the development placed in proxim- 

 ity to others in which the spores are irregularly grouped. Although, owing to mod- 

 ern researches, we know much more about the real nature of the cystocarps than was 

 known a few years ago, it must be admitted that the suborders of Floridece are far 

 from satisfactory. As a matter of fact, the order is a very natural one, and, as is the 

 case with most natural orders, the species and genera pass so gradually into one an- 

 other that sharply marked divisions are out of the question. At the base of the order 

 is a small number of genera whose position is doubtful, owing to our lack of informa- 

 tion about the fructification. Then come the Porphyrece, in which we have fronds of 

 a single layer of cells (PorpJiyra) and certain cells grow out so as to form a very short 



