OF ARTS AND SCIENCES. 47 



latter. Recently Reiiike and Schraltz found in one of the species for- 

 merly described as C. inirahilis cystocarpic fruit which enabled them 

 to ascertain its true affinities. They placed it among the Gelidiaceaj, 

 and gave to ft the new generic name of Ilarveyella.* Their reasons 

 for placing it in a new genus were twofold. They rightly thought 

 C mi'rabi/is to be widely different from G. Poh/ssiphonue. Besides this, 

 C Pohjsiplioniai w;\^ described before C. mirabiUs in Keinsch's original 

 account, so that the former is to be regarded as the type of the genus 

 Choreocolax ratlier than the latter. Besides these notes, Choreocolax 

 and Harveyella are scarcely more than mentioned by name in a few 

 other places. Schmitz in his arrangement of the genera of the Flori- 

 defe t places them both among the Gelidiaceae. Batters mentions 

 them also in his List of Berwick Algre, % and reports the collection of 

 tetrasporlc specimens of 0. PulyslphouicE, but has nothing new to add 

 regai'dlng them. I'hus it will be seen that the literature concerning 

 these interesting parasites is very scanty. 



Choreocolax Polysiphonice grows, as has been already stated, upon 

 Polysiphonla fastigiata, a common alga along the Northern New Eng- 

 land coast. The parasite was sufficiently abundant at Nahant, Mass., 

 to be collected in consideraljle quantities from the middle of Novem- 

 ber to the latter part of the following March. I found it also at 

 Newport, R. I., growing on the Polysiphonia, on the more exposed 

 points. C. Polysiphonice has been collected by Dr. W. A. Setchell 

 at various points along Long Island Sound, though its host is much 

 less common there than farther north. Mr, F, S. Collins has sent 

 me specimens he found at Mount Desert, on the Maine coast, during 

 the month of July, 1890. From all reports, however, it is found no- 

 where in such quantities as at Nahant. Batters § mentions C. Polysi- 

 phonice as having been collected on the British coast at Berwick Bay, 

 but adds that it is rare. The distribution of this alga, then, is fairly 

 wide, and It is probable that wherever its host is found it may also 

 be expected in greater or less quantities. 



To the naked eye the fronds of Choreocolax appear as small whitish 

 brown dots of varial)le size, situated almost always in the dichoto- 

 mies of the Polysiphonia. In some specimens collected at Nahant, 

 almost every axil except the ones of the very youngest branches was 



* Alpenflora der west. Ostspp. Deiitsch. Anth,, Kiel, 1880, p 28. 

 t Systemat. Uebersicht der bislier bekannten Gatt. der Florideen. Flora, 

 1889, Heft V p 489. 

 t Pages 1-26 and 142. 

 § List of Berwick Algae, p. 142. 



