ganietangia, from which are derived swarmspores or 

 gametes. 



Three species of Codium (out of fifteen) occur in British 

 seas, but only one, C. tomentosum, occurs in the L.M.B.C. 

 district. 



Codium. 



The genus Codium was first estabhshed by Stackliouse 

 {Ner. Brit., 1795 — 1801), to receive the type previously 

 known as Fiiciis tome)itosiis. This name the same 

 authority altered to Lamarkea in the second edition of 

 his work, and included under it two species C. tomentosiun 

 and the plant now know^n as G. bursa. Lamouroux, in 

 1813, proposed the name Spongodium for the genus, 

 whilst, later still, Cabrera re-christened these and other 

 species by placing them in the newly constituted genus 

 Agardhia. C. Agardh reverted to the name suggested by 

 Stackhouse, and, at the same time, re-defined the genus. 

 Decaisne subsequently sub-divided the then known species 

 into two genera, one represented by Codium tomentosum, 

 for which he retained the name of Codium, the other 

 represented by Codium bursa, to which he gave the name 

 of Spongodium. 



An elaborate and authoritative account of the genus 

 was, in 1885, published by the great Swedish Algologist, 

 J. A. Agardh (Till Algernes Systematik, Lunds Univ. 



o 



Arsskr., XXIII.). In this monograph he includes all 

 previously known species under the single generic heading 

 of Codium, sub-dividing them, however, into tribes, which 

 are, on the whole, co-extensive with the genera established 

 by preceding authors. 



The first tribe established by Agardh is that represented 

 by Codium adluvrens, Cabr., where the thallus is firml}' 

 fixed to the sui^tratiuu in the form of a dark green, gela- 



