516 Mr. C. Mereschkowsky on Californian Diatoms. 
201. Biddulphia aurita (Lyngb.), Bréb. San Pedro, rare; 
Monterey, common. [M. 
202. Biddulphia Baileyi, W. Sm. San Pedro, rare. [M.] 
203. Biddulphia Edwardsii, Febiger. Northern California, 
common. [G., M.] 
Usually with 2-4 very robust spines. 
204. Biddulphia levis, var. minor. San Pedro, common; 
Northern California, rare. [M.] 
Diameter attaining 0°112 mm. 
205. Biddulphia longicrucis, Grev. (Diatomeentaf. zus. f. e. 
Fr. pl. xxi. fig. 10). Calif. guano. [Gv.] 
206. Biddulphia pulchella, Gray. San Pedro, very common. 
[M.] 
207. Biddulphia reticulata, Roper. San Pedro, somewhat 
rare. [M.] 
208. Biddulphia reticulata, var. rhombica, Mer. Northern 
California, very rare. [M.] 
209. Biddulphia Roperiana, Grev. San Pedro, not very rare; 
Calif. guano. [Gv., M.] 
210. Biddulphia simplex, Mer., sp.n. (PI. IV. figs. 28-30.) 
San Pedro, rare. [M.] 
Valve delicate, membranaceous, elliptic-lanceolate, with 
ends acute, without spines or any visible structure. Grrdle- 
face with lateral margins straight (fig. 29) or with valves 
being separated by only a very slight concavity (fig. 30, a, a) 
from the connecting membrane ; processes short, acute, middle 
part of the valve slightly convex, showing two concave 
arcuate lines uniting in the centre. Length of the valve 
0:042 mm., breadth 0-018 mm. 
211. Biddulphia tumida, Roper. (Diatomeent. zusamm. f. e. 
Fr. pl. xxvi. figs. 18,19). Calif. guano. [Gv.] 
212. Biddulphia Tuomeyi, Bail. Calif. guano; San Pedro, 
rare. [Gv., M.] 
In San Pedro I have seen a narrow valve 0°187 mm. in 
length and 0°042 mm. in breadth, probably belonging to a 
variety of this species. 
213. Biddulphia (Cerataulus) turgida, W. Sm. San Pedro, 
rare. [M.] 
214. Porpeia quadrata, Grev. (Diatomeentaf. zus. f. e. Fr. 
pl. Ixvii. fig. 20). San Pedro, very rare. [M.] 
