564 Howe: Phycological studies 



very short anastomosing processes. [P 



24; PLATE 26, FIGURES 1-6. 



Near low-water mark in the Bahama Islands : no. jgSi, type 

 (Cave Cays, Exuma Chain, 19 February 1905, M. A. H.) ; nos. 

 341 jb and 3421b (Rose Island) ; 710. 4186a (Stocking Island, 



Exuma Harbor). 



Halimcda faviilosa simulates in form, size and habit certain con- 

 ditions of H. tridens (Ell. & Soland.) Lamour. or of H. tridcns 

 Monile (Ell. & Soland.) * but is easily and constantly distinguished 

 by the very large peripheral utricles (i 10-260 /i vs. 33— 68^a in H. 

 tridcns) which, on drying, collapse or withdraw into the subtend- 

 ing and separating lime-cups, leaving the surface conspicuously 

 and rather beautifully favulose. In the character of the peripheral 

 utricles the species suggests H. macropliysa Ask., though its 

 utricles are sometimes even larger than in that, according to the 

 measurements given by Askenasy and by Barton, but it has the 

 size, form, and node-characters of the H, tridcns group instead of 

 the H. Tuna-H. macropliysa alliance. It evidently bears a relation 

 to H. tridcns similar to that of H, viacropJiysa to H, Tnna, In case 

 of three out of the four collection numbers cited above, H.favidosa 

 was found growing in company with H. tride?is or 7/. tridcns 

 Moniie and resembling them so much in habit that the distinctive 

 characters escaped observation at the time of gathering. 



• There is a possibility that HaVuncda favidosa will prove to be 

 //. brcvicaidis Kiitz., f described from the Bahamas, but the 

 doubts in regard to this can probably never be resolved unless 

 Kiitzing's specimen, which now seems to be lost, is found. J H. 

 brexncaulis^ according to Kiitzing's figure and brief description, 

 might equally well be a form of the extremely variable H, tridens^ 

 which IS more abundant in the same region. The short stipe of 

 '' brcvicanlis'' has no special significance, but the apparently flac- 

 cid habit and tapering branches, it must be admitted, are rather 

 suggestive of H.favniosa. Yet flaccid, decumbent conditions of 



H. tridens occur. Kutzing describes the si 

 as terete, w^hile in all the specimens of H.fc 



H. 



*Halimeda tridens Monile (Ell. & Soland.) 



CornlUna Monile Ell. & Soland. Nat. Hist. Zooph. no. //. 20, f, c. 1786. 

 fTab. Phyc. 8 : 11.//. 23. / 2, 1S5S. 

 % See ** Addendum " on page 5S6. 



