Mr. C. Mereschkowsky on Californian Diatoms, 295 
36. Navicula mutica, forma Cohnii, Hilse. Lost Spring 
Ranche, foss.? [C.] 
37. Navicula ostrearia, Turp. (N. fusiformis, var. ostrearia). 
San Pedro, not very common. {[M.]| 
I have not seen the characteristic blue colour at the apices 
of the frustule; but this is not a constant character, and in 
the Black Sea, where this species is very common, I often 
met with specimens showing no trace of blue colour. 
38. Navicula pennata, A. S. Northern California, not rare. 
[M.] 
I have already mentioned the occurrence of this species in 
the Glacial Ocean (Wankarema, North Siberia) *. 
39. Navicula pretexta, Khr. [C., M.|] 
I have seen only a fragment of a valve in a slide containing 
diatoms from San Pedro Bay. 
40. Navicula punctulata, W. Sm. Rather common in a 
laguna near San Pedro. [C., M.] 
41. Navicula (Libellus) reticulata, Mer. San Pedro, Santa 
Catalina Island, very common. [M.] 
A detailed description of this species will be found in my 
paper on the Diatoms of the Black Sea, where it is also very 
common, as well as in the Mediterranean (Villefranche). 
Its endochrome is very curious, the single plate forming a 
complicated network covering the surface of both connecting 
membranes with transverse bands crossing the interior of 
the cellule. 
42. Pinnularia cruciformis, Donk. Northern California, rare. 
[M. ] 
43. Brebissonia Boeckii (Kiitz.),Grun. San Pedro, rare. [M.] 
Length 0:097 mm., breadth of the valve 0°021 mm., strive 
8 in 0°01 mm. in the middle (not 10, as stated by Cleve). 
44, Frustulia interposita, Lewis. Oakland, Calif., brackish. 
[C.] 
45. Anomeoneis sculpta, var. major, Cl. Santa Rosa, 
brackish. [C.] 
AG. Scoliotropis latestriata, Cl. [C.] 
47. Gomphonema kamtschaticum, var. californica, Grun. 
Monterey, not very rare; San Francisco. [C., M.] 
According to Cleve, length 0°03 mm., strie 15 in 0-01 mm., 
valve linear. 
* See my paper ‘ On Polynesian Diatoms,” chapter iy, 
