34 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



show a rich flora, as has been noted on the Atlantic side, where in the 

 accessible spots near the Canal it is poor, but rich only a few miles each 

 side. The flora of this district might be expected to show Caribbean 

 tendencies, but as yet there is little evidence of this. 



It is worth while to look separately at the results of the deep-sea 

 dredging. The Chlorophyceae is obviously not the group most likely to 

 characterize dredged material. From the present series of collections no 

 considerable number of species were solely secured by dredging. In 

 general, the species of Chlorophyceae most often secured by dredging 

 were Codiums, Halimedas, and Ostreobium, with a few scattering things. 

 These did really at times come from quite deep water. 



The Phaeophyceae were much more often present in the hauls. This 

 was especially true of Dictyotaceae, Sporochnaceae, Desmarestiaceae, 

 Laminariaceae, and would have been true of Fucaceae also if more of the 

 dredging had been done in the shallow-water Sargassum beds. Especially 

 notable finds were dredged in the genera Zosterocarpus, Eiseniaj Sporoch- 

 nus, SpatoglossmUj Dictyopteris, and Desmarestia. Altogether, more nov- 

 elties were dredged in this group than were expected ; but, when one tries 

 to attribute this to a south-temperate element, one finds that the genera 

 are more often warm-water ones than not, and only Desmarestia and 

 Eisenia are distinctly of cold-water affinities. 



The Rhodophyceae, where one expects most of the dredged records 

 to come, were mostly shallow-water species. As one looks for distinctively 

 deep-water genera, one finds Scinaia, Asparagopsis, Peyssonnelia, Litho- 

 thammuin, Aeodes, Halymeniaj Kallymenia, A gardhiella, Sarcodiotheca, 

 Gracilariaj Fauchea, Botryocladia, Griffithsia, and most of the genera of 

 the Delesseriaceae to be groups nearly limited to deeper water. Of these, 

 A gardhiella, Griffithsia, and Scinaia are perhaps genera of cool-water 

 tendencies, but for the most part the others include species more like those 

 of the tropics and subtropics than otherwise. 



SUMMARY OF ALGAL DISTRIBUTION 



Considering the frequency of the species in the chief algal groups, we 

 find the same general proportional relations here as in other comparable 

 parts of the world, although perhaps a little accentuated. Granting that 

 the data are quite imperfect, there is yet probable significance in the per- 

 centage of species in the groups as compared from certain major areas. 

 For instance, on the northeast North American coast the flora, subarctic 

 and cool temperate, shows a ratio of approximately 20 per cent of Chloro- 

 phycean species, 33 per cent of Phaeophycean, and 42 per cent of Rhodo- 



