132 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



Common from Nantucket southward. 



A summer plant which attains perfection during the month of July, disappearing 

 later in the summer. It is sometimes found washed ashore in large quantities after a 

 storm. The species has heen known for some time, hut until recently it has passed 

 for a form of G. corallina, a species common in Europe. It differs from that species in 

 several respects. The antheridia form a sort of cap over the top of the terminal 

 cells of the male plant, which is considerably smaller than the female plant and has a 

 different habit, in consequence of which it was called a variety, var. globifera, by Har- 

 vey. The female and tetrasporic plants more closely resemble the true G. corallina. 

 They do not end in large globose cells, as in the male plant, but the largest cells are 

 below the tip, which is tapering and acute. When the tetrasporic plant has narrower 

 and more acute cells than usual it constitutes the var. tenuis of the Nereis. The slen- 

 derest specimens, however, are usually sterile. In the structure of the procarp this 

 species differs considerably from G. corallina as described by Janczewski. There is 

 only one trichogyne instead of two, as in the last-named species. The procarp begins 

 by the growth of a hemispherical cell at the upper part of an articulation. The cell is 

 then divided into two parts by a partition parallel to the base. It is from the lower 

 cell thus formed that the involucre is formed, and from the upper arise the carpogenic 

 cells in the following way: By usually four obliqiie partitions there are formed four 

 external hemispherical cells and a central pyramidal cell with a broad base. By sub- 

 sequent division of one of the hemispherical cells, generally of the one lying nearest 

 the axis of the plant, there is cut off a cell which divides into three smaller granular 

 cells, the upper of which grows into a trichogyne. The spores are formed by the sub- 

 sequent growth of the other three hemispherical cells. There are two sets of hair-like 

 organs which arise from the upper border of the cells iu this species; one set is short 

 and granular, consisting of a cuboidal basal cell with short corymbose filaments; 

 the other set occupies a similar position, but the hairs are long and hyaline,. consist- 

 ing of a long basal cell, which bears at its apex a whorl of three or more cells, which 

 in turn bear other whorls, the whole hair being several times compound. 



HALUEUS, Kiitz. 



(From ale, salt, and ovpa, a tail.) 

 Fronds monosipbonous, branching, beset throughout with short, ap- 

 proximate, incurved, di-trichotomous, whorled, secondary branches ; tet- 

 raspores tripartite, attached to the inner side of special branches, 

 arranged in whorls one above another ; antheridia in similar position, 

 forming closely verticillate tufts; favellse terminal on short branches. 



A genus composed of one, or according to some writers two, species, separated from 

 Griffithsia principally by the character of the frond. 



H. equisetifolius, Kiitz. (Griffithsia equisetifolia, Ag.; Phyc. Brit., 

 PI. 67.) 



Fronds four to eight inches long, arising from a disk, irregularly 

 branching, secondary branches trichotomous below, dichotoinous above, 

 much incurved, densely covering the branches, rhizoidal descending fila- 

 ments given off from some of the lower branches. 



Brooklyn, N. Y.<? 



A plant resembling a Cladostephns, except that its color is a dirty red. The species 

 is very doubtfully known on our coast. It is mentioned in the Nereis as having been 

 sent to Harvey by Mr. Hooper, of Brooklyn, but there is no definite information as to 

 the locality where the plant was collected. 



