222 University of California Puhlications in Botany [Vol. 8 



'acters until more extensive investigations have been undertaken. 

 None of our species has been subjected to an examination of this sort, 

 although they all seem to be made up of multinucleate segments. "We 

 shall consequently adopt Spongomorpha for our species instead of 

 following the revision of Wille and adopting Acrosiphonia. 



Kjellman (1893) has laid great stress on the variation in the posi- 

 tion of the fertile segments. We have not been able^ as yet, to study 

 this character in many of our species and can not, therefore, judge 

 properly of distinctions founded on such characters. It is very desir- 

 able that a study of the forms, arrangement and dates of formation 

 of the fertile segments be made for our various species, and in widely 

 separated localities. 



We have followed Collins (1909) very largely in the descriptions 

 and limitations of our species, but have examined all our west coast 

 plants carefully. As a result, we have found it necessary to depart 

 from his account in some minor details and to differ from him in 

 referring some of our plants. Of the seven species recognized by us, 

 five are supposedly restricted to the North Pacific Ocean and orig- 

 inally named by Kuprecht (as species of Conferva). Two, however, 

 are assumed to be identical with North Atlantic species. Possibly 

 some of ovir species may be identical rather with some of the species 

 distributed by Kjellman under Acrosiphonm, but we have not been 

 able to make sufficiently certain of this to place any under his names. 



The species of our coast are most numerous along the northern 

 range, i.e., from Puget Sound northward. Spongomorpha coalita, 

 however, ranges from Sitka, Alaska to just north of Point Concep- 

 tion, California. A form referred to Spongomorpha arcta has been 

 found in one locality in this same range, but we are inclined to 

 associate it rather with S. Mertensii. 



Key to the Species 



1. Branches all blunt and rounded at the apex 2 



1. Branches sometimes rounded, sometimes acute at the apex 5 



2. Hooked branchlets present 5. S. Mertensii (p. 227) 



2. Branchlets never hooked 3 



3. Slender, not over 100^ in diam. at tip 1. S. arcta (p. 223) 



3. Stouter, 200^, or over, in diam. at tip 4 



4. Walls of segments thin, not striate 2. S. Hystrix (p. 224) 



4. Walls of segments thick, striate 3. S. duriuscula (p. 225) 



5. Hooked branchlets absent 4. S. saxatilis (p. 226) 



5. Hooked branchlets present 6 



6. Hooked branchlets always simple 6. S. spinescens (p. 229) 



6. Hooked branchlets usually compound or branched 7. S. coalita (p. 230) 



