1^20] . Setchell-Gardner : Chlorophyceae 221 



Kuetzing, Phyc. Gen., 1843, p. 273. Cladophora {Spongomorpha) 

 Kuetzing, Spec. Alg., 1849, p. 417. 



As originally founded by Kuetzing, Spongomorpha included two 

 species, Coiiferva uncialis Ag. and Conferva aggregata Ag., the latter 

 now considered to be a synonym of Conferva lanosa Roth. Since these 

 two species have generally been regarded as varieties of one, we may 

 say that Spongomorpha Kuetzing has for its tyipe S. lanosa (Roth) 

 Kuetzing. In the Phycologia Germanica (1845, p. 237), Kuetzing 

 credited Spongomorpha with nine species, six of which are now 

 referred under Spongomorpha lanosa or its variety uncialis, while 

 three are members of the Ectoearpaceae. He also placed the genus 

 near Ectocarpiis and well removed from his Cladophora and Aegagro- 

 pila. In the Species Algarum (1849, p. 387 et seq.), Kuetzing placed 

 both Spongomorpha and Aegagropila as subdivisions (subgenera?) 

 under Cladophora. In this arrangement he extended Spongomorpha 

 to embrace twenty-one species, but did not include under this sub- 

 division his section " Comosae" (1849, p. 389) of six species now gen- 

 erally referred to Spongomorpha arcta. Kuetzing 's extension, how- 

 ever, is sufficient to indicate a conception decidedly advanced beyond 

 his first proposal. His first conception (1843) of the character of 

 Spongomorpha was the dense habit, but later (1849) he called atten- 

 tion to the slender, descending rhizoidal branches. In 1854, Kuetzing 

 reviewed Spongomorpha as a genus, illustrating the various species 

 belonging to it (1854, p. 16 et seq., and 1855, p. 29). Kuetzing 's idea, 

 even then, was founded chiefly on habit. 



J. G. Agardh (1846, p. 12) founded a genus Acrosiphonia {" Acro- 

 liphonia" as printed) which was based largely upon Conferva lanosa 

 Roth and C. arcta Dillw. The chief character given is that of having 

 the upper seg-ments long, while the lower are very short. 



We find, therefore, two genera, or generic conceptions, of prac- 

 tically the same content, but which have usually been included under 

 Cladophora. Kjellman was the first to recall attention to Spongo- 

 morpha (1883, p. 304 et seq.), but in 1893, he reviewed J. G. Agardh 's 

 genus Acrosiphonia and substituted it for Spongomorpha. A later 

 proposal is that of Wille (1899, p. 281, 1900, p. 238) who would' 

 restrict Spongomorpha to the original type species, S. lanosa, on 

 account of its uninucleate segments, and apply Acrosiphonia to the 

 other species because of their multinucleate segments. To this dis- 

 tinction he adheres in a later article (1909, pp. 117, 118). It seems 

 to us desirable to defer judgment on the value of the nuclear char- 



