no. 9 



ALGAE TAYLOR 



original C. zvembaerense Schmidle (1898, p. 33, pi. 2, fig. 8), although 

 of about the same size. The lateral semicell faces are not as distinc- 

 tively elevated and thickened in these plants as they are in those from 

 the Clipperton lagoon. There are a number of other forms recorded 

 with approximately the same size and practically the same contour 

 from face view (or with but slightly more broadly truncate apices), 



1-7, Cosmarium clippertonensis, face (1, 2, 4, 5), edge (3) and polar views 

 (6, 7), all X 940. 8, Closterium parvulum forma, X 375- 9, Closterium parvuhwi 

 near v. majus, X 375- 10-12, Cosmarium subprotumidum, polar (1), face (n), 

 and edge (12) views, X 940. 



but usually the lateral faces are not markedly elevated, or evidence on 

 this point, from a good polar view, is quite lacking. 



Very common in the lagoon, particularly in the strainings from the 

 Lyngbya masses, Clipperton Island, Mexico (Schmitt 21), July 21, 

 I938- " 



Cosmarium subprotumidum Nordstedt, forma. Text figs. 10-12. 



These plants were generally a little large for the species, with the 

 lateral granules very small and obscure, those on the central pro- 

 tuberance large but low and not very refractive. 



