470 



BULLETIN OF THE BUREAU OF FISHERIES. 



THE WARM-WATER SUBLITTORAL FORMATION. 



A characteristic warm-water sublittoral formation is present during the summer 

 in the more sheltered regions of the Bay and Sound — that is, in the upper portion of 

 Buzzards Bay and in the narrow and easterly portions of Vineyard Sound. The con- 

 ditions in these regions are much more varied than in the lower portion of the Bay and 

 the westerly portion of the Sound occupied by the cool-water sublittoral formation. For 

 example, the conditions and flora of the upper end of Buzzards Bay are quite different 

 from those around Woods Hole. Further subdivisions of the warm-water sublittoral 

 formation could undoubtedly be made to advantage, but it would be unwise to attempt 

 to do so on our present information. Accordingly, we shall treat the warm-water 

 sublittoral as a very large and widely distributed formation, excluding, however, those 

 algse which are characteristically associated with beds of Zostera in an assemblage called 

 here the Zostera forrpation (c). 



The species in these lists (as in those of the cool-water sublittoral formation) 

 preceded by an asterisk (*) are the larger or more abundant forms which dominate 

 the formation; species which are rare or occasional are followed by an (o). 



The most interesting and noteworthy species in the warm-water sublittoral forma- 

 tion are those which have not been reported at all north of Cape Cod or are present 

 there only under exceptional conditions. This list includes the following species: 



Cladophora albida. 



Ectocarpus granulosus var. ten- 

 uis (o). 



E. lutosus (o). 



E. Mitcliella; (o). 



Cladostephus spongiosus (o). 

 *C. verticillatus. 



Rhadinocladia Farlowii (o). 



Striaria attenuata (o). 

 *Arthrocladia villosa. 



Elachista stellaris var. Chordae 

 (o). 



Myriactis pulvinata var. minor. 



Stilophora rhizodes (o). 



Sargassum bacciferum (o, float- 

 ing in Sound). 

 *S. Filipendula. 



S. Filipendula var. subedenta- 

 tum. 



Scinaia furcellata. 

 *Antithaninion cruciatum. 



A. cruciatum var. radicans (o). 



A. plumula (o). 



Callithamnion Baileyi var. 

 laxum. 

 *C. roseum. 



C. tetragonum. 



Ceramium botryocarpum (o). 



C. capri-cornu (o). 

 *C. tenuissimum. 

 ♦Griffithsia tenuis. 



Pleonosporium Borreri. 

 *Seirospora Griffithsiana. 



*Spermothamnion Tumeri. 

 *Spyridia filamentosa. 



Chondria dasyphylla. 



C. sedifolia (o). 

 *Polysiphonia fibrillosa. 



P. vestita (o). 



Rhodomela Rochei. 



R. virgata (o). 



Actinococcus aggregatus (o). 



Gymnogongrus Griffithsiae (o). 



Gracilaria confervoides (o). 



G. multipartita. 



G. multipartita var. angustissi- 

 ma (o). 



Hypnea muciformis. 



Lithothamnion polymorphum. 



Another group of species comprises those which range both north and south of Cape 

 Cod, some of them being also conspicuous in the cool- water sublittoral formation (a). 

 The list includes the following : 



Cha?tomorpha linum. 



Cladophora albida var. refracta. 



C. arcta. 



C. glaucescens. 



C. gracilis. 



C. hirta (o). 



C. lanosa. 



C. Rudolphian?.. 



C. rupestris. 



Bryopsis hypnoides (o). 



B. plumosa (o). 

 *Ectocarpus confervoides. 

 *E. fasciculatus. 



E. granulosus 

 *E. siliculosus. 



P)-laiella littoralis. 

 Sphacelaria cirrhosa. 

 S. radicans. 



Punctaria plantaginea ((j). 

 Desmarestia aculeata (o). 

 *Desmarestia viridis. 

 Dictyosiphon hippuroides. 



E. siliculosus var. hiemalis (o). Myriotrichia filiformis. 



