192 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



place in each segment, so that the arrangement of the anther- 



ozoids is represented by the formula 64 (— — , — — , — ) 



N 4 4 4/ 



(fig. 27). To this type belong P. leucosticata, P. laciniata, 

 and it may be predicted, judging from the carpospores, 

 that P. naiadtmi also belongs to this section, the antheridia 

 in this species being as yet undetected. 



Among the distromatic forms the remainder of the types 

 are found. First we have the P. amplissima type, with 

 eight carpospores and sixteen antherozoids, and the form- 



ul. 8 (f 4, I) (fig. 24) and x6 (i^^, 'A±, ^) (fig. 



26) ; then the P. tniniata type, with four carpospores and 



eight antherozoids, and the formulae 4 ( — , ^, c\ (fig. 23) 



and 8 (^^, ^^, ^ (fig. 25). To this belong P. min- 



iata, P. tenuissima and P. ahyssicola. 



Of the two other distromatic species which occur on the 

 Pacific Coast, but one form of fruit has been found, so that 

 they can hardly be brought forward as types. 



III. Distribution. 



It is almost impossible to obtain a correct idea of the dis- 

 tribution of the older species of Po7-fhyra, as frequently the 

 name P. laciniata was applied to various species which since 

 have been separated from it. However, the author believes 

 that it may be said with some degree of certainty that P. 

 laciniata occurs on the western shores of Europe, from the 

 Norwegian Polar Sea (71"^ N. lat.) to the Mediterranean 

 (40° N. lat.) and on the Atlantic coast of North America 

 from Greenland (67° N. lat.) to New Jersey (40^ N. lat.). 

 It has never been authoritatively reported from the eastern 

 shores of Asia; for though older authors have mentioned 

 it, yet P. laciniata was not included by Kjellman (1897) 

 among the Japanese species, and he even expresses some 

 doubt as to its occurrence. On the Pacific Coast of North 



