60 COLLINS AND HERVEY. 



form, less branched, the lower joints longer, the upper joints ending 

 in three cylindrical lobes. 



Forma gracilis Borgesen, 1913, p. Ill, fig. 89. Joints small, sub- 

 circular in outline, not strongly calcified. 



These forms all pass into each other. Borgesen considers H. Monile 

 and H. simulans also as forms of this species, and it may be that he is 

 right as to the former, but the differences between these two, and the 

 three forms that we consider to belong to H. tridens, are greater than 

 the differences among the latter. Gepp and Borgesen prefer the name 

 H. mcrassata to H. tridens; the case for the former is stated by Bor- 

 gesen, 1911, p. 136, that for H. tridens by Howe, 1907, p. 501. 



4. H. Monile (Ell. & Sol.) Lamouroux, 1812, p. 186; Collins, 

 1909, p. 399; P. B.-A., No. 1915; H. incrassata forma vionilis Barton, 

 1901, p. 27, PL IV, fig. 40; Corallina vionilis Ellis & Solander, 1786, 

 p. 110, PI. XX, fig. c. Inlet, Jan., Oct., Dec, Bailey's Bay, Jan., 

 Walsingham, Nov., Tucker's Town, Dec, Hervey; Hungry Bay, 

 April, Collins. Rather common; the forms recognized by Borgesen 

 both occur here. 



Forma robusta Borgesen, 1913, p. 113, fig. 90. Densely branched, 

 the upper joints cylindrical, the lower tripartite and sometimes resem- 

 bling the upper joints of H. tridens forma tripartita. 



Forma cylindrica Borgesen, 1913, p. 113, fig. 91. Less branched, 

 the joints nearly all cylindrical. 



Family BRYOPSIDACEAE. 



Bryopsis Lamouroux. 



1. Ramuli distichous. 2. B. pennata. 



1. Ramuli not distichous. 2. 



2. Main branches virgate, with very slender ramuh. 3. B. Duchassaingii. 



2. Outline pyramidal, branching of several orders, no sharp distinction 



between branches and ramuli. 1. B. hj^pnoides. 



1. B. hypnoides Lamouroux, 1809, p. 333; 1809b, p. 135, PI. I, 

 fig. 2, a & b; Collins, 1909, p. 403. Harrington Sound, Jan., Feb., 

 April, Walsingham, March, Hervey; Kemp, May, as B. plumosa, in 

 part; cave by Gravelly Bay, April, Collins. 



Forma prolongata'j. G. Agardh, 1886, p. 28; P. B.-A., No. 1870; 

 B. hypnoides Harvey, 1846-51, PI. CXIX. Harrington Sound, May, 

 Dec, Collins; Old Ferry, April, Hervey. 



2. B. Duchassaingii J. G. Agardh, 1854, p. 107; Collins, 1909, 



