108 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



NAVICULA LONGA (Gregory) Ralfs 



(Donkin, Brit. Diat., pi. 8, fig. 3; Schmidt, Atlas, pi. 47, fig. 68.) 



Another species occurring at both Campeche Bay and the Philip- 

 pine Islands. 



NAVICULA LYRA Ehrenberg 



(Ehrenberg, Amer., pi. 1, sec. 1, fig. 9a; Gregory, Diat., Clyde, pi. 1, fig. 13; 

 Schmidt, Atlas, pi. 2, figs. 24-25; pi. 3, figs. 11-12; Van Heurck, Synopsis, pi. 10, 

 figs. 1-2.) 



The type form of this cosmopolitan species is not common in the 

 Philippine Islands, but is mainly represented by several of its many 

 varieties, as var. recta (Schmidt, Atlas, pi. 2, fig. 18), var. subcarinata 

 (Schmidt, Atlas, pi. 2, fig. 5). Var. insignis (Schmidt, Atlas, pi. 2, 

 fig. 27), and var. elliptica (Schmidt, Atlas, pi. 2, fig. 34) also present, 

 hardly belong to this category and might receive separate names. 



NAVICULA MADAGASCARENSIS Cleve 



Plate 25, fig. 4 



(Le Diat., vol. 1, p. 23, pi. 4, fig. 2.) 



The type locality was Tamatava, Madagascar. A very robust form 

 of this rare diatom is here figured, the measurements of which are — 

 Length, 0.110; width, 0.056; lines, 6.5 in 0.01 mm. 



NAVICULA MARGARITA A. Schmidt 



(Schmidt, Atlas, pi. 174, fig. 17. 



This species is also exclusively a Campeche Bay-Philippine Islands 

 form. 



NAVICULA MARGINATA Lewis 



(Lewis, New and Rare Diat., p. 62, pi. 2, fig. 1; Schmidt, Atlas, pi. 160, figs. 

 21, 28, 31.) 



This strikingly beautiful and variable diatom is widely dispersed. 

 Among other places it is found both at Campeche Bay and the Philip- 

 pine Islands, especially the variety which Castracane calls N. janischii 

 in the Report of the Challenger Expedition, plate 30, figure 5, and to 

 which Cleve has appended the unnecessary term, "forma brevis." 

 Its artful simulation of the genus Mastogloia caused Brun and Grunow 

 to put varieties of it in that genus, and Cleve to name a variety with- 

 out the usual median constriction " Dictyoneis thumii" (Cleve, Nav. 

 Diat., vol. 1, pi. 5, fig. 33). 



NAVICULA MAXIMA Gregory 



(Gregory, Glenshira Diat., pi. 4, fig. 19; Schmidt, Atlas, pi. 50, figs. 19-21, 

 33, 36.) 



The resemblance of this species to N. liber W. Smith causes De 

 Toni (Syl. Alg., p. 158) to remove Gregory's own example in Dia- 

 toms of the Clyde, plate 1, figure 13, to N. liber., as well as that of 



