54 ULVACEJE. 



especially when in fructification, the colour being wholly derived from the fructifying 

 cells. The colour also generally becomes more intense and more purple after steeping 

 in fresh water, and in the process of drying ; and the dried plant has a very glossy 

 surface, like satin. Sometimes it adheres to paper and sometimes not ; and it always 

 shrinks considerably in drying. 



II. BANGIA. Lyngb. 



Frond thread-shaped, tubular, composed of numerous radiating cellules, disposed in 

 transverse rows, and enclosed within a hyaline continuous sheath. Spores purple, one 

 formed in each cell of the frond. 



This genus was founded by Lyngbye on the Conf. fusco-purpurea of Dillwyn, and 

 several other Algte, both marine and of fresh water, which are more or less nearly allied 

 to it. Some of these have been properly removed. The genus stiU contains some 

 anomalous species, but the three following appear to me to be con-generic. The genus 

 was first placed by Greville in UlvaceaB. This position has been questioned, and I was 

 formerly disposed to concur with those who refer it to the neighbourhood oiLyngbya in 

 Oscillatorieas ; but a careful examination, especially of B. vermicularis, has now con- 

 vinced me that Bangia cannot be far removed from Porphyra^ to which it bears the 

 same relation that Enteromorpha bears to LUva. 



1. Baxgia fuscopurpiirea, Lyngb. ; filaments elongated, simple, decumbent, nearly 

 straight, capillary, here and there constricted, forming a brownish-purple, glossy stratum ; 

 granules several in each transverse band, dark purple. Lyngb. Hycl. Dan. p. 83, t. 24. 

 Greu. Alg. Brit., p. 177- Wyatt, Alg. Damn., Ko. 167. Harv. Fhyc. Brit., t. \)(). 

 Kiitz. Sp. Alg. p. 360. B. atropurpurea, Ay. Syat. p. 76. Alg. Eur. t. 25. Conferva 

 fuscopurpurea, Dillw. t. 92. E. Bot. t. 2055, and C. atropurpurea, Dilliv. t. 103. 

 E. Bot. t. 2085. 



Hab. On rocks and wood-work between tide marks. Newfoundland, Herb. Mon- 

 tagne. Narragansett Pier, Prof. Bailey. Little Compton, Mr. Olney. Providence, ^[. 

 Charles Giraud. Lynn, Mass. Mrs. Estes. (v. v.). 



This is attached to rocks and stones, or to woodwork, and occurs in stratified patches 

 of indefinite extent, of a dark purple colour. The filaments are 2-3 inches long, and 

 float freely in the water, lying down in a fleece when left by the retreating tide. They 

 vary greatly in diameter according to age, and the miscroscopic characters are equally 

 varied in young and old specimens. In the young state the filament is formed of a 



