126 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



NITZSCHIA CAMPECHIANA Grunow 



Plate 28, figs. 3-4 

 (Grunow, New Species, Nitz. Micro. Journ., 1880, p. 395, pi. 13, fig. 16.) 



This is identical with N. alata Leuduger-Fortmorel (Diat. Malaisie, 

 p. 24, pi. 2, fig. 11, 1892). It is quite probable that N. swperba 

 Leuduger-Fortmorel (Diat. Ceyl., p. 40, pi. 8, fig. 83, 1879) is also the 

 same, although the double row of unskillfully formed beads at the 

 middle of the valves, found in N. campechiana and N. alata, is lack- 

 ing in N. swperba, and the ends are slightly more pointed. All are 

 abundant in the Philippine Islands; and a series of many intermediate 

 forms goes far to prove that the above-mentioned marks of distinction 

 vary individual cases in every conceivable way. I have, at least 

 temporarily, held N. swperba separate, as thereby simplifying idenifica- 

 tion; but a specific difference will probably eventually be found unten- 

 able. In that case, the oldest name, N. swperba, would replace 

 N. campecliiana and N. alata. The similar N. bukensis Peragallo 

 (Diat., Samoa, pi. 2, fig. 6, 1911) should also be mentioned here as an 

 important variety of N. swperba. Of course, all of these may be said 

 to belong to the N. nicobarica Grunow group of Nitzcliiae. (See this 

 in Reise F. Nov., pi. 1A, fig. 4.) 



As the name indicates, this is another species found in Campeche 

 Bay and the Philippine Islands. 



NITZSCHIA COCCONEIFORMIS Grunow 



Plate 28, fig. 5. 



(Grunow, New Species, Nitz., p. 395, pi. 12, fig. 5; Peragallo, Diat., France, 

 pi. 75, fig. 15.) 



Both the type form and an interesting variety of this rare diatom 

 were found, the latter figured here. 



NITZSCHIA DISTANS Gregory 



(Geogorv, Diat., Clvde, p. 58, pi. 14, fig. 103; Van Heurck, Synopsis, pi. 62, fig. 

 10.) 



Both the type form and the curious variety which. Grunow calls 

 var. twmescens were found, the latter being another example of dia- 

 toms common to the floras of Campeche Bay and the Philippine 

 Islands. 



NITZSCHIA FLUMINENSIS Grunow 



(Grunow Oest. Diat., Wien. Verh., 1862, p. 581, pi. 12, fig. 35; Van Heurck 

 Synopsis, pi. 62, figs. 3-4.) 



Here is included Grunow's N. majuscula, which Van Heurck rightly 

 considers to be a variety of this species; figured in Van Heurck, 

 Synopsis, plate 62, figure 5. The type is found in both Campeche 

 Bay and the Philippine Islands, var. majuscula in only these two 

 places. 



