62 COLLINS AND HERVEY. 



Var. secunda (Harv.) comb. nov. ; B. plumosa var. secunda Harvey, 

 1858, p. 31, PL XLV. A, figs. 1-3; B. Harveyana Collins, 1909, p. 405. 

 This variety shows a certain dorsiventral arrangement, the ramuli 

 on both edges of the rachis curving towards each other on one side. 



Var. Leprieurii (Kiitz.) comb, nov.; B. Leprieurii Kiitzing, 1849, 

 p. 490; 1856, p. 27, PI. LXXV, fig. 2; Collins, 1909, p. 404. In this 

 variety the ramuli are in short secund series, separated by short vacant 

 spaces. 



Family DERBESIACEAE. 

 Derbesia Solier. 



1. Filaments 100-600 /x diam. 3. D. Lamourouxii. 



1. Filaments less than 100 yu diam. 2. 



2. Filaments 40-50 jj. diam., dichotomously branched. 



1. D. vaucheriaeformis. 

 2. Filaments 50-70 n diam., simple or with short lateral branches. 



2. D. marina. 



1. D. VAUCHERIAEFORMIS (Harv.) J. G. Agardh, 1886, p. 34; 

 Collins, 1909, p. 406; B. tenuissima Farlow, 1881, p. 60, PI. IV, fig. 4; 

 Chhrodesmis vaucheriaeformis Harvey, 1858, p. 30, PI. XL. D. On 

 Didyopteris Justii, Gravelly Bay, Aug., Collins. With sporangia. 



2. D. MARINA (Lyng.) Kjellnian, 1883, p. 16; Collins, 1909, p. 407; 

 Vaucheria marina Lyngbye, 1819, p. 79, PI. XXII. On Acantho- 

 phora spicifera, Hungry Bay, May, Collins. With sporangia. 



3. D. Lamourouxii (J. Ag.) Solier, 1847, p. 162, PI. IX, figs. 18- 

 30; Collins, 1909, p. 407; P. B.-A., No. 2168 ; Bryopsis Balhisiana var. 

 Lamourouxii J. G. Agardh, 1842, p. 18. Castle Harbor, near landing 

 at Tucker's Town, March, Hervey. The fronds are much stouter than 

 in the two other species of the genus, sometimes simple, sometimes 

 with a few irregular tufts of ramuli. Old and denuded plants of 

 Bryopsis have some resemblance to it, but always show the scars of 

 fallen ramuli. 



Family CAULERPACEAE. 

 Caulerpa Lamouroux. 



1. Stolon and fronds filiform, without distinct ramuh. 1. C. fastigiata. 



1. Stolon and fronds different in character. 2. 



2. Fronds very slender, ramuli whorled, near the summit. 3. 



2. Fronds stouter, ramuli not in distinct whorls. 4. 



