LYNGBYA. 219 



" About the globule which is at the base of this sheath, are 

 developed, in the form of a rosette, the first articulations of 

 the filaments, as is seen in^. 7. They are cuneiform ; some 

 slightly bi-lobed, give origin to two cells, and so determine the 

 dichotomy of the filaments. 



" The variety, /3 soluta, which I have sometimes found 

 amongst examples of the ordinary type, might be considered 

 as another species on account of its filaments, which are not 

 depressed, and are free in their whole length, but certain 

 fronds of the ordinary type may be regarded as connecting 

 the two forms ; I therefore do not think that they can be 

 separated. I have always observed that the filaments of the 

 variety /3 do not preserve, in ramifying, a dichotomous dis- 

 position so exact as in Coleocheete scutata, &c." 



In all those specimens of this most interesting production 

 which I have examined, the sheaths and cilia have been al- 

 together wanting. In some cases, however, the point of 

 attachment of the sheaths to the cells could be perceived. 

 The natural position of the genus is certainly near to Bulbo- 

 chcete. 



Sub-fam. ii. ULOTHRICEJE. 



20. LYNGBYA Ag. 



Char. Filaments simple, subulate, and shining. Z6ospores 



several in each cell, escaping through rents in the walls 



of the cells. 

 Sphceroplea Berk. Ulothrix Kiitzing, Phyc. Gen. p. 251. 



Sphceroplea Kiitzing, 1. c. 

 Name in honour of M. Lyngbye, author of an excellent 



work on the Alga of Denmark. 



The genera Lyngbya and Sphceroplea are undoubtedly 

 identical, and one of the terms must of necessity be sup- 

 pressed. Bangia also differs but slightly from the genus 

 Lyngbya, and its abolition seems called for. Kiitzing has 

 constituted a new genus for the reception of Conf. zonata 

 (SpharopleacrispaHerk.}, Ulothrix, preserving also the genus 

 Sphceroplea, the type of which he makes Conf. annularia Roth. 



