Mr. C. Mereschkowsky on Californian Diatoms, 507 
three undulations, upper end bent in a hook as in Gr. angu- 
losa. 
142. Grammatophora costata, Mer., sp.n. (PI. V. figs. 15, 
16.) Monterey, very rare. [M.] 
Valve somewhat broad, perfectly linear, with broadly 
rounded apices; structure composed of costz 8°5 to 9 in 
0°01 mm.; intercostal spaces with a double row of small but 
distinct puncta forming decussating rows, pseudoraphe rather 
indistinct. Length 0°0417—0:0565 mm., breadth of the valve 
0:0115-0:0133 mm.; diameter of the openings 0:0076- 
0:013 mm. 
I have seen only three valves of this species, which has 
the same structure of the valves as in Achnanthes longipes or 
Diploneis Smithit. The septa, as can easily be seen from 
fig. 16, form more than one undulation (probably two or 
three) ; the openings of the septa are quadrangular, in small 
specimens they are rounded. 
143. Grammatophora decussata, Mer. Monterey, very rare. 
[ M.] 
For the description of this species see my paper ‘‘ On Poly- 
nesian Diatoms.”’ 
144. Grammatophora marina, var. communis, Grun. San 
Pedro, Redondo, common; Monterey, not rare. [M.] 
145. Grammatophora marina, var. hawaiensis, Mer. Mon- 
terey, rare. [M.] 
Length 0:065 mm., breadth of the girdle-face 0-024 mm., 
diameter of openings 0:0065 mm. Described and figured in 
“ Polynesian Diatoms.” 
146. Grammatophora marina, var. macilenta, W. Sm. San 
Pedro. [M.] 
147. Grammatophora maxima, Grun. San Pedro, very rare. 
(M.] 
This might be the G. robusta, Dippel. I do not understand 
the difference existing between the latter and G. maxima. 
There are a number of other species and varieties of 
Grammatophora to be found in California, which, however, 
require further examination and a careful comparison with 
similar forms from other localities. 
148. Plagiogramma californicum, Grev. San Pedro, very 
rare; Calif. guano. [Gv., M.] 
Occurs in Californian guano. Plagiogramma tnequale, 
Greville, seems to me to be the same as this species. 
d5* 
