120 COLLINS AND HERVEY. 



case are they quite typical L. setacea, that it seems best to consider 

 them merely forms of the common and variable L. ohtusa. A specimen 

 in the Farlow herbarium, collected by G. Tucker, No. 10, is near 

 L. impHcata J. G. Agardh, 1852, p. 745, and a similar form was found 

 on the outer reef, Ely's Harbor, July, Collins, and this also we have 

 considered as a local form of L. obtusa. This form is found rather 

 commonly when dredging. 



6. L. PANicuLATA (Ag.) J. G. Agardh, 1852, p. 755; Chondria 

 obtvsa var. panicvlata Agardh, 1822, p. 343. Faxon; Dingle Bay, 

 Jan., Buildings Bay, Mangrove Bay, Feb., Hervey. Connected by 

 intermediate forms with L. obtusa, but in its typical form quite dis- 

 tinct by the firmer, little adhesive substance, the narrowly pyramidal 

 form of the frond and of its principal divisions, the main axis distinctly 

 projecting. 



Chondria Agardh. 



1. Rhizoids frequent; tetraspores in specialized branches. 4. C. polj-rhiza. 

 1. No rhizoids except at extreme base; tetraspores in normal branches. 2. 



2. Ends of pericentral cells showing as a wavy line across the frond. 



1. C. curviUneata. 



2. Pericentral cells not showing externally. 3. 



3. Hamuli acute or subacute. 3. C. atropurpurea. 



3. RamuU blunt or truncate. 2. C. dasj^jhylla. 



1, C. curvilineata sp. nov.; P. B.-A., No. 2039. Fronde tenui, 

 axibus principalibus diametro ^ mm. raro superantibus, ramos paullo 

 minores paucos pluresve alternantes ferentibus, ordinum duorum, 

 raro plures, cylindricos vel ad basin et apicem paullo contractos; 

 puncto vegetationis ad fundo foveae apicalis, folia brevia ferente; 

 foliis similibus secimdum ramos sparsis; segmentis diam. duplo longi- 

 oribus; cellulis corticalibus diam. duplo longioribus; apicibus cellu- 

 larum centralium per corticem manifestis ut lineis curvis, latere 

 convexo apicem versus; cystocarpiis sessilibus; substantia submolli; 

 colore rubro obscuro. Plate II, figs. 10-11. 



Frond slender, main axes seldom reaching ^ mm. diam., with more or 

 less numerous alternate branches of two orders, seldom more, of only 

 slightly less diam., cylindrical or slightly contracted at base and apex; 

 growing point at bottom of an apical pit, with a tuft of short leaves, 

 similar leaves occurring also at scattered points on branches; seg- 

 ments about 2 diam. long; cortical cells about twice as long as broad; 

 swollen apices of pericentral cells showing through the cortication as 



