'29G Mr. C. Meresclikowsky 07i Californian Diatoms. 



48. Trachyneis aspera, Elir. San Pedro, common ; Monterey, 

 rather common, [M.] 



49. Trachyneis aspera, var. intermedia, Grun. San Pedro, 

 not rare. [jM] 



Valve lanceolate, axial area rather broad on one side of the 

 raphe, absent on the otlier. 



50. Plenrosigma sestuarii, Br^b. San Pedro, rare. [C, M.J 



51. Plenrosigma cnspidatnm, CI. San Pedro, not rare. [M.] 

 Endochrome composed of four narrow bands, having the 



same disposition as in P. Nonnanii. 



52. Plenrosigma elongatum, W. Sm. Laguna near San 



Pedro, marine and brackish, common. [M.] 

 Endochrome composed of four elongate and straight 

 bands. 



53. Plenrosigma formosnm. W. Sm. Northern California, 

 rather common. [M.] 



Endocluome composed of four very elongate and tortuous 

 bands. 



54. Plenrosigma formosnm, var. longissima, Grun. San Pedro, 

 not rare. [M.] 



Length of the valve 0-463 0-o38 



Breadth 0-042 0-055 



Oblique strije 10-11 11-12-5 



Valves broader than in the type species ; differs from 

 var. laleari'ca, which has the same broad valves, by the 

 strife, which in the latter are 8-9 in 0*01 mm. 



55. Plenrosigma latum, CI. Santa Monica, on Macrocystis, 



rather common. [M.] 

 Endochrome composed of four bands forming several undu- 

 lations of exactly the same kind as in P. Normanii and 

 P. cuspidatum. 



56. Plenrosigma nnbecnla, W. Sm. Santa Monica, amongst 



Macrocystis ; Monterey, common. [C, M.] 

 Endochrome composed of four elongate and very tortuous 

 bands. 



57. Plenrosigma rhombenm, Grun. [C] 



58. Gyi'osigma attenuatnm, Kiitz. San Pedro, rare. [M.] 



59. Gyrosigma balticnm, var. californica, Grun. Laguna 



near San Pedro, not rare. [C, JM.] 

 Endochrome composed of two perforated chromatophore- 

 plates ; perforations narrow, oblique. 



