568 EHODOMELACEAE. 



4. Chondria polyrhiza Collins & Hervey, Proc. Am. Acad. 53: 121. pi. 2. f. 12. 



1917. 



In shallow water down to IS meters {fide Collins), Atwood Cay (with C. curvi- 

 lincata) : Bermuda and American Virgin Islands. Type from Bermuda. 



5. Chondria curvilineata Collins & Hervey, Proc. Am. Acad. 53: 120. pi. 2. f. 



10, 11. 1917. 



On corals and among other algae, near low-water mark, more or less iridescent 

 when living, Atwood Cay, Mar iguana, and Great Ragged Island : Bermuda. Type 

 from Bermuda. 



6. Chondria Collinsiana M. A. Howe, sp. now 



Fronds erect, solitary or gregarious, mostly 3-8 cm. high, texture rather 

 soft, color (dried) stramineous to yellowish rose; branching rather sparsely 

 virgate or paniculate-virgate, with well-defined main axes mostly 0.4-0.75 mm. 

 in diameter; pericentral siphons in all parts with conspicuous saucer-shaped, 

 dome-shaped, or cup-shaped thickenings of their anterior end-walls, forming 

 crescentrie or crenate lines in regular transverse series, visible through cortex, 

 the longitudinal walls also occasionally showing somewhat similar or more 

 lenticular thickenings; surface cells mostly 65-160 /x X 26-AO /j. in surface view, 

 2-5 times as long as wide; ultimate ramuli fusiform-obovoid to cylindric-clavate 

 or cylindric, mostly 0.75-4.5 mm. long, and 0.28-0.45 mm. in greatest diameter, 

 patent or subdivarieate, straight or slightly recurved, solitary and rather widely 

 spaced (0.5^-2.5 mm. apart), moderately attenuate or constricted at base, the 

 apex obtuse or subtruncate, crowned with conspicuous tufts of trichoblasts 

 ("leaves") often 0.75 mm. or more in length and becoming yellowish brown or 

 fuscous on drying; the growing point immersed and concealed in an apical pit 

 (sect. Coelo chondria) ; tetrasporangia confined to apical part of ramulus or 

 sometimes occupying the whole of it. 



Chondria Collinsiana differs from C. curvilineata as indicated in above key and 

 also in its yellowish or rose rather than purple-red or brownish red color. 



On Penicillus, Rhipocephahts, Halimcda, Thalassia, etc., in shallow water, Mari- 

 guana {Howe 5386 type), New Providence, Berry Islands, Watling's Island, and 

 Great Bahama. 



7. Chondria dasyphylla (Woodw.) Ag. Syn. Alg. Scand. xviii. 1S17. 



Fucus dasyphyllus Woodw. Trans. Linn. Soc. 2: 239. pi. 23. f. 1. 1794. 

 Chondria sedifolia Harv. Ner. Bor.-Am. 2: 19. pi. 18G. 1853. 

 Chondriopsis dasyphylla J. Ag. Sp. Alg. 2: 809. 1863. 

 Carpocaulon dasyphyllum Kuntze, loc. cit. 



In shallow water, New Providence, Berry Islands, and Great Bahama : Massa- 

 chusetts to Bermuda ; Florida ; and Barbados ; southern Europe and the Mediterra- 

 nean. Type from eastern England. 



8. Chondria leptacremon (Melv.) De-Toni, Syll. Alg. 4: 848. 1903. 



Chondriopsis leptacremon Melv. Jour. Bot. 26: 333. pi. 284. f. 2a, 2b. 1888. 



In shallow water in Rhizophora associations, Exuma Chain and Watling's 

 Island : Florida. Type from Key West, Florida. 



3. ACANTHOPHORA Lamour. Essai 44. 1813. 



Spines not occurring on the main axes; main branches narrowly 



virgate. 1- A - spicifera. 



Spines of occasional occurrence on the main axes ; branching 



very irregular. 2 - A - muscoides. 



