MARINE DIATOMS OF THE PHILIPPINE ISLANDS 109 



Kalfs in Pritchard, Infusoria, plate 7, figure 75. Lagerstadt (Diat., 

 Bohusl., p. 43.) names a specimen, N. liber, var. maxima. Admitting 

 the nearness of some of the varieties to each, it is best to keep the 

 dissimilar types in separate species. 



NAVICULA MENDICA, new species 



Plate 23, fig. 3 



Valve convex narrow, lanceolate, the sides running straight from 

 middle to apices, which are not produced but are rounded and massive 

 because of a thickening of the silica wall; markings of short, beaded, 

 slightly diagonal lines in four rows, two inner and two marginal ; all 

 four rows have the lines set wide apart, the interspaces being twice 

 the width of the lines; the two marginal rows are alike, their lines 

 very short; the two inner rows are unlike, one being close to and 

 parallel with the rhaphe and made up of very short lines, the other 

 of longer lines, midway between the margin and the rhaphe and 

 parallel with the margin ; rhaphe straight, the middle ends approaching 

 closely, the outer ends stopping short of the apices. 



Length, 0.062; width, 0.016; 4.7 lines in 0.01 mm. 



That this is close to N. biseriata Petit (Journ. Roy. Micro. Soc, 1878J 

 p. 241, pi. 32, fig. 33) and to N. ricliardsoniana O'Meara (Irish Diat., 

 p. 339, pi. 32, fig. 33) is evident; but it differs from both by its very 

 angular outline, by the unsymmetry of median rows of lines, and by 

 the shortness of these lines in three of the four rows. It further 

 differs from N. richardsoniana in the remoteness of the rhaphe ends 

 from the apices of the valve, and from N. biseriata in the absence of 

 the " semis tauros " at the central nodule. In other words, there is, 

 with a certain resemblance, the same degree of valid difference 

 between these as between N. califomica Greville and N. hennedyi W. 

 Smith. O'Meara says his species closely resembles N. nitescens Greg- 

 ory, which it certainly does ; but it would be difficult to trace any 

 resemblance between that diatom and the present species. While 

 dealing with the above combination it may be in place to remark 

 that to those who can not accept Cleve's subdivision of the genus 

 Navicula as of generic rank, his arbitrary changing of N. biseriata 

 Petit into Caloneis biseriata (Petit) Cleve and then appropriating that 

 name for another Navicula — "Diploneis biseriata CI." — causes much 

 confusion. This latter diatom I have also found in the Philippine 

 Islands and my position, with that of Van Heurck and many other 

 diatomists being against the dismemberment of Navicula, has com- 

 pelled me to give to Cleve's species a new name Navicula mimula Mann, 

 which see. 



Type.— Cat. No. 43650, U.S.N.M. 



