292 Mr. ©. Mereschkowsky on Californian Diatoms. 
XXXIX.—A List of Californian Diatoms. 
By C. MERESCHKOWSKY. 
[Plates IV. & V.] 
THE recent marine Diatoms of California are interesting in 
more than one respect. In the first place a list of Californian 
Diatoms will form a desirable contribution to our knowledge 
of the geographical distribution of these little Algee, the more 
so as the Diatom flora of the Pacific is as yet but very little 
known. ‘Then, again, the study of recent Californian Diatoms 
as compared with the extensive fossil deposits of this region 
is of interest in order to ascertain which of the fossil forms 
have disappeared and which are still living, and whether these 
latter have changed in the course of time or not. 
It is for these reasons that [I undertook the study of Cali- 
fornian Diatoms, which I intend to carry out as completely as 
possible—a task which will certainly require a number of 
years in order to accomplish it with a certain degree of com- 
pleteness. At the present time [ will only give a short 
preliminary list, partly composed of forms observed by myself 
so far as I have been able to determine them, partly of some 
species which have been previously noticed by other diatomists, 
especially by Cleve in his ‘Synopsis of the Naviculoid 
Diatoms,’ as wel] as by a few others (Grunow, Greville). 
This list will also contain the species which I have already 
mentioned and partly described in a previous publication 
entitled ‘On Polynesian Diatoms,’ the fourth chapter of which 
deals with Diatoms belonging to the Californian coast. 
The reader will find in this paper the description of a 
number of new species and varieties, accompanied by 
figures. Some of them are small and delicate forms which 
1 have observed in a living state or in preserved crude 
material, and which can hardly be expected to be found in 
slides, as such forms usually completely disappear during 
the cleaning of the material. Certain details of their structure 
(such as the striz when very fine) could not, for this reason, 
be ascertained. 
In the list I indicate the person who has observed the 
species by the first letter of his name—C. meaning Cleve, 
G. Grunow, Gy. Greville, and M. myself. 
1. Diploneis bombus, var. bullata, Cl. [C.] 
2. Diploneis bombus, var. densestriata, Cl. [C. | 
3. Diploneis contigua, var. eudoxia, A. 8. [C.] 
