MARINE DIATOMS OF THE PHILIPPINE ISLANDS 135 



PLEUROSIGMA FORMOSUM W. Smith 



(Smith, Brit. Diat., pi. 20, fig. 195; Peragallo, Pleuro., pi. 1, fig. 1; H. L. 

 Smith, Types, No. 694.) 



Peragallo's figures of this fine species are all defective in outline. 

 He designates his plate 1, figure 4, as the true type, which is far from 

 the case, as can be seen by comparison with W. Smith's original figure. 

 The nearest to this in Peragallo's monograph is his plate 1, figure 1. 



PLEUROSIGMA HAMULIFERUM Brun 



(Brun, Diat. Jap., pi. 9, fig. 5; Peragallo, Pleuro., pi. 5, fig. 31; also pi. 4, 

 fig. 12, misnamed.) 



This species with the curiously hooked rhaphe was first found in 

 the fossil deposit at Sendai, Japan; but recent specimens were sub- 

 sequently found in Yokohama Bay, Japan, and now in the Philippine 

 Islands. 



PLEUROSIGMA HEROS Cleve 



(Cleve, Nav. Diat., vol. 1, p. 44, pi. 4, fig. 20.) 

 Previously found only at Macassar Straits. 



PLEUROSIGMA ITALICUM Peragallo 



(Peragallo, Pleuro., p. 8, pi. 3, fig. 10.) 



The similarity of this species, hitherto found only at Naples, Italy, 

 is so close to P. marinum Donkin that its independence is to be 

 questioned. 



PLEUROSIGMA JAPONICUM Castracane 



(Castracane, Chall., Exp., p. 38, pi. 29, fig. 14.) 



The unquestionable two-line oblique marking of this species has 

 been noted in the discussion of this genus and its subdivisions. 



PLEUROSIGMA LANCEOLATUM Donkin 



(Micro. Journ., 1858, pi. 3, fig. 4; not Peragallo, Pleuro., pi. 5, fig. 14.) 



Roper's P. transversale in the Quarterly Journal of Microscopical 

 Science for 1858, plate 3, figure 11, is practically the same. As 

 noted above, Peragallo's figure does not represent this diatom. 



PLEUROSIGMA LATUM Cleve 



(Cleve and Grunow, Arct. Diat., pi. 3, fig. 68; Peragallo, Pleuro., pi. 3, figs. 

 16-18.) 



PLEUROSIGMA NAVICULACEUM Brebisson 



(Br6bisson, Diat., Cherb., pi. 1, fig. 7; Peragallo, Pleuro., pi. 4, figs. 19-22.) 



PLEUROSIGMA NICOBARICUM Grunow 



(Grunow, Reise F. Nov., p. 101, pi. 1A, fig. 20; Peragallo, Pleuro., pi. 4, fig. 9 

 (not pi. 4, figs. 10-12).) 



The figures of Peragallo excluded above have no relation to this 

 species. His No. 12, and perhaps No. 11, is P. hamuliferum Brun. 

 35035—25 10 



