294 Mr. C. Mereschkowsky on Californian Diatoms, 
in the fig. 24of PlateIV. The raphe is to be seen asa crack 
in the wall of the fiustule, and the areas are deep invagina- 
tions of the surface of the valve on both sides of the raphe. 
22. Navicula forcipata, var. nummularia, Grey. Calif. guano. 
[C.] 
23. Navicula (Rhoiconeis) garkeana, Gr. California, North 
Pacific. [C.] 
24. Navicula (Rhoiconeis) genuflexa, Kiitz. San Pedro, 
rather common. {M.| 
The endochrome is composed of two chromatophore-plates, 
with a deep and narrow sinus on each side in the middle of 
the plates, and usually two, sometimes more, eleoplasts 
(Pl. TV. tte, 25). 
25, Navicula granulata, Bail. (Navicula Baileyana, Gr.). 
Calif. guano; North California, rare. [C., M.] 
26. Navicula (Libellus) Grevillei, Ag. [C.] 
27. Navicula (Libellus) hamulifera, Grun.? San Pedro. [M.| 
28. Navicula Hennedyi, W.Sm. [C.]| 
29. Navicula Hennedyi, var. californica, Grev. [C.] 
30, Navicula Hennedyi, var. circumsecta, Grun. [C.] 
It is on account of its synonym Nav. californica, A.S., 
that I have placed this species in the list of Californian 
Diatoms, although Cleve does not mention it in his ‘Synopsis’ 
as belonging to this locality. 
31. Navicula irrorata, Grev. Calif. guano. [C.] 
32. Navicula libellus, Greg. Santa Monica, amongst J/acro- 
cystis, not very common. [M.] 
Length 0:084 mm. Hndochrome composed of two chroma- 
tophore-plates of the same shape and disposition as in 
N. complanata*, but the inner angles of the plates are united 
by a loop or narrow band crossing the interior of the cell, so 
that in reality there is but one plate. Iam very much in- 
clined to think that such a connecting band exists also in 
N. complanata. 
33. Navicula lyra, var. dilatata, A. 8S. San Pedro. Rare. 
[M.] 
34, Navicula lyra, var. recta, Grev. Calif. guano. [C.] 
35, Navicula (Schyzonema) mollis, W. Sm. San Pedro, 
rather common. [M.] 
* Cleve, ‘Synopsis of the Nayiculoid Diatoms,’ part 1. p. 1538, 
