138 REPOKT OF COMMISSIONER OF FISH AND FISHERIES. 

 C. CORYMBOSUM, Ag. 



" Fronds capillary, rather regularly decompound-dichotomous, branches 

 erecto-patent, corymbose, fastigiate, apices forcipate, lower joints four to 

 five times longer than broad, upper joints subequal j tetraspores naked, 

 emergent, secund on the outer side of the branches, lower portion rest- 

 ing on the cortical layer." (Agardh, Epicrisis, p. 03.) 



Atlantic coast of North America. 



This species is said by Agardh to resemble C. fasiUjiatum iu its ramifications, but 

 with more expanded branches, and to differ iu having a violet color and a different ar- 

 rangement of the tetraspores. From this it would appear that the two species are 

 practically distinguished hy the different position of the tetraspores. With regard to 

 their i^ositiou iu C. fastigiatinn, as has already been said, Agardh and Harvey do not 

 agree. 



C. TENUissiMUM, (Lyngb.) Ag. 



Fronds rosy- red, two to four inches high, densely tufted, capillary, 

 decompound-dichotomous, branches erect, patent, apices forcipate -, tet- 

 raspores borne on the swollen nodes, usually on the outer side, often 

 several together j favelhne lateral, invoiucrate. 



Yar. ARACHNOIDEUM, Ag. 



Fronds more slender than in the type, tetraspores exserted, secund 

 on the outer side of the branches, solitary or several together. 



Yar. PATENTissiMUM, Harv. 



Fronds small, dichotomies distant and patent, the branches ending in 

 dichotomo-multifld, divaricating, corymboso-fastigiate branchlets. 



On Zostera and algoe. 



Common in Long Island Sound; Gloucester, Mass., 2Irs. Davis; 

 Europe. 



The present species, according to Agardh, includes the C. nodosum of the Phycologia 

 Britannica, but Harvey's plate certainly does not correctly represent the tetraspores of 

 the tyx)ical form of the species. In the type the nodes are swollen, especially on the 

 upper margin, and the rather large tetraspores x>roject beyond the cortical cells, 

 usually on the outer side of the node, and there are frequently from two to four together. 

 In the var. arachnoideum the tetraspores become almost naked, being only slightly 

 covered by the cortical cells in their lower part. The var. paientissimum of Harvey has 

 a somewhat different ramification from the type. It must be admitted that the limits 

 of C. tenuissimiim are not well marked, and it may be that iu the present case wo 

 have confused two distinct species. 



C. Capri-Gornu, (Eeinsch). (Rormoceras Cajyri-CornUjJiemBch, Con- 

 trib. ad Alg. et Fung., p. 57, PI. 47. — C. Yoimgii, Farlow, Kept. U. S. Fish 

 Comm., 1875.) 



Fronds brownish purple, one to three inches high, filaments setaceous, 

 repeatedly dichotomous, divisions erecto-patent, ultimate divisions sub- 



