191^] Setchell: The Scinaia Assemblage 101 



which has a diameter of 1.5 iiini. (dried) ; (2) a specimen collected at 

 Gilbert's Bar. Florida by A. IT. Curtiss (TTerb. Univ. Calif., No. 

 96361), also about 1.5 mm. in diameter (dried); and (3) a specimen 

 collected at the Bermuda Islands by Dr. W. G. Farlow in 1881. While 

 it is difficult to be absolutely certain Avhether the narrower forms are 

 flattened or not, they seem to be so and they agree in structure with 

 No. 836 Phycotheca Boreali- Americana. Harvey states (1853, p. 137) 

 that his Key West specimens of Scinaia furcellata varied in diameter 

 about a tenth of an inch (about 2 mm.) to a quarter of an inch (about 

 6 mm.). Yet he says nothing of their being flattened. The structure 

 of the axis and its disappearing below (flattening out) is as definitely 

 to be seen in the narrower as in the broader specimens. In structure 

 Scinaia complanata is closely related to Scinaia latifrons, as will be 

 discussed further below, but the species is smaller and narrower and 

 has the cystocarps scattered with no indication of aggregation at the 

 margins. 



From Sci)taia furccllala, tlie other North Atlantic species, it is to be 

 distinguished, not only by its being complanate but by the fact that 

 the outer ends of the utricles are flattened and by the utricles them- 

 selves being flattened rectangular in shape as well as by minor pecu- 

 liarities in each case. 



In connection with Scinaia complanata, Isymenia angusta J. Ag. 

 (1899, p. 66) has been mentioned (cf. F. S. Collins, 1901, No. 836, 

 and 1906, p. 110). An examination of the material under this name 

 in Herb. J. Agardh at Lund shows seven specimens; three were col- 

 lected at Indian Eiver Inlet, Florida, by ]\Irs. G. A. Hall iuul were 

 evidently considered by J. G. Agardh to be young and not typical. 

 One of them, at least, is certainly Scinaia complanata and the other 

 two appear to be. Of the other four, one from Indian River, Florida, 

 coHected by ]Mrs. G. A. Plall, is typical Scinaia complanata, as is 

 also another specimen from Florida collected by Mrs. Hall, while the 

 ii'iuaining two are seemingly species of Ilalynienia, or a related genus, 

 one of them, collected at Key West by Mrs. G. A. Hall, l)eing tetra- 

 spofir. while the other collected at the same locality and from the 

 .Mtlville Collection, is cystocarpic. Isymenia angusta, then, is Scinaia 

 complanata in part and in \y,\v\ possibly a i)roper species, the latliM- 

 matter not to be settled at the ijresent time. 



From the North Pacific species, Scinaia Johnstoniae and Scinaia 

 japonica, Scinaia complanata differs, not only in being complanate, but 

 also particularly in having the colorless cells of the epidermis flattened 



