NO. 10 DAWSON : MARINE ALGAE, GULF OF CALIFORNIA 215 



shapes, and sizes may occur side by side in the same part of a plant. The 

 species of the Gulf of California, as recognized in this paper, are distin- 

 guished first by their gross morphology and habit, secondarily by utricle 

 characters. Since gross morphology is modified by age, we must consider 

 the possibility that small plants such as have been placed under the name 

 C odium cervicorne may likely be young stages of a species like C. simu- 

 lans. A plant collected in summer such as that named C. unilaterale may 

 be a more aged form of a plant similar to that named C. Brandegeei. A 

 floating plant such as C. atnplivesiculatum may be a growth form of C. 

 unilaterale or C. longiramosum from the same station. C. anastomosans 

 was described from immature material but has juvenile characters which 

 suggest its possible distinctness. All of these problems must be investigated 

 in the field before any of the specific determinations given here can be con- 

 firmed. However, with the information at hand, the following modifica- 

 tions in nomenclature seem justified. 



A re-examination of the type of C odium simulans and of C. Brande- 

 geei indicates that these two plants are essentially indistinguishable. Setch- 

 ell and Gardner saw similarities between the two but stated no points of 

 distinction. The type of C. Brandegeei is a fragmentary specimen with no 

 positive data as to either locality or date. It does, however, match C. sim- 

 ulans and other comparative specimens so closely that its synonymy here 

 can be stated with certainty. Codium unilaterale is an entity which is rec- 

 ognized by Setchell in recent study notes as being closely related to C. 

 simulans. The plant was collected in the summer and is undoubtedly an 

 older growth form of this species, exhibiting the same fundamental char- 

 acters merely in a somewhat larger, more expanded form. On the other 

 hand, the type of C. cervicorne, though future investigation alone can 

 verify this, shows every evidence of being the juvenile form of the same 

 species. In all these plants the utricles are of the same shape, the size vary- 

 ing directly with that of the specimens. Thin end-walls in the utricles of 

 C. unilaterale are conspicuous but may not be of genetic importance. 



Codiuin unilaterale is one of that remarkable set of specimens collected 

 in July, 1921, by Johnston (74) in the lagoon at Pond Island. Pond 

 Island's "rattlesnake harbor" is only about 150 yards long, the whole is- 

 land being less than a square mile in area. In this lagoon Johnston col- 

 lected several specimens which Setchell and Gardner segregated under 

 three names, C. unilaterale, C. amplivesiculatum, and C. longiramosum, 

 by reason of the strikingly different appearance of the dried plants. In 

 February, 1940, the author collected in the same lagoon specimens which 



