572 EHODOMELACEAE. 



9. MURRAYELLA Schmitz, Ber. Deuts. Bot. Ges. 11: 227. 1893. 

 1. Murrayella periclados (Ag.) Schmitz, loe. cit. 



Hutchinsia periclados Ag. Sp. Alg. 2: 101. 1828. 



Polysiphonia periclados Kiitz. Sp. Alg. 822. 1849. 



Bosfrychia Tuomeyi Harv. Ner. Bor.-Am. 2: 58. pi. 14E. 1853. 



BostrycMa periclados J. Ag. Sp. Alg. 2: 860. 1863. 



Polysiphonia Binderi SoncL; Kiitz. Tab. Phyc. 14: 16. pi. 45. f. a, b. 1864. 



In rock caverns, on the roots of Rhizophora, etc., between the tide-lines and in 

 shallow water, New Providence and Bimini : Bermuda and Florida to northern 

 South America. Type from St. Croix. 



10. AMPHIBIA Stackh. Mem. Soc. Imp. Nat. Moscou 2: 58, 89. 1809. 



Scorpiura Stackh. Ner. Brit, ix, xi. 1816 [eel. 2 not seen]. 



Bostrychia Mont, in Sagra, Hist. Cuba, PL Cell. 39. 1838. Not Bostrychia 



Fr. Sv. Vet. Akad. Handl. 1818: 119. 1818. 

 Helicothamnion Kiitz. Linnaea 17: 105. 1843; Plryc. Gen. 433. 1843. 

 Stictosiphonia Harv. in Hook, f . II. Antaret. 483. 1847. 



Fronds stout and rigid, having commonly a spread of 2.5-5 cm. ; sections of main 

 axes showing 37 series of pericentral cells ; monosiphonous 



apices usually short or more commonly wanting. 1. A. Montagnei. 



Fronds smaller ; sections of main axes showing 1-3 series of 

 pericentral cells. 

 Branchlets bearing numerous long deflexed and incurved often 

 branched monosiphonous ramelli 2050 cells long, these cells 

 26-55 u long, longer than broad ; plants repent or prostrate, 

 forming thin mats ; sections of main axes showing 2 or 3 

 series of pericentral cells. 2. A. tenella. 



Branchlets without monosiphonous ramelli or occasionally 

 terminating in monosiphonous prolongations 210 

 (rarely -20) cells long, these cells 15-26 long, shorter 

 than broad at least in proximal parts ; main axes show- 

 ing 1 or 2 series of pericentral cells ; plants forming 

 dense mats. 

 Regularly bi-tri-pinnate ; ultimate branchlets, 75-200 u 



(6-12 cells) long; main branches prostrate or ascending. 3. A. Sertularia. 

 Bi-tri-pinnate or often more or less quadrifarious through 

 the development of two rows of ventral branches near 

 the bases of the lateral branches ; ultimate branchlets 

 200-750 u (1210 segments or cells) long ; main branches 

 deflexed or drooping. 4. A. pectinata. 



1. Amphibia Montagnei (Harv.) Kuntze, Rev. Gen. PL 2: 881. 1891. 



BostrycMa Montagnei Harv. Ner. Bor.-Am. 2: 55. pi. 14B. 1853. 



On roots of Rhizophora and rarely on other objects, usually just above the low- 

 water mark, Bimini, Great Bahama, Exuma Chain, and Watling's Island : Ber- 

 muda ; Florida ; Cuba ; and Jamaica. Type from Key West, Florida. 



2. Amphibia tenella (Vahl) Kuntze, Rev. Gen. PL 2: 882. 1891. 



Fucus tenellus Vahl, Nat. Selsk. Skr. 5 2 : 45. 1802. 



Rhodomela calamistrata Mont. Ann. Sei. Nat. Bot. II. 8: 354. 1837. 



Bostrychia calamistrata Mont.; Harv. Ner. Bor.-Am. 2: 56. pi. 14C. 1853. 



Bostrychia tenella J. Ag. Sp. Alg. 2: 869. 1863. 



Bostrychia Vieillardi Kiitz. Tab. Phyc. 15: 10. pi. 26. f. a-e. 1865. 



Creeping on rocks, roots of Rhizophora, pneumatophores of Avicennia, etc., near 

 the high-water mark, New Providence, Rose Island, Great Bahama, Gun Cay, Wat- 

 ling's Island, and Caicos Islands : Bermuda ; Florida ; and the West Indies generally ; 

 widely distributed in the warmer seas. Type from St. Croix. 



