;-^0 Prof. p. T. Cleve and Mr. C. Meresclikowsky on 



dissimilar valves, and is most akin to Cocconeis flexella, KUtz., 

 = Ac}man th idiu m jlexellum . ] 



Amphora alpha (p. 106) is doubtful ; possibly a form of 

 A. quadrata (Greg. ?), Perag. 



Amphora beta (p. 107) : doubtful ; possibly A. sulcata 

 (Breb.?), Perag. 



Amphora gamma (p. 108) ^'■B.antzschia " marina (Donk.). 



Amphora delta (p. 108) seems to be akin to A. alata, Perag. 



Amphora zeta (p. 109): doubtful; perhaps A. Icevis, var. 

 minida, CI. 



Amphora ostrearia (p. Ill) certainly does not represent 

 this well-known species, but possibly A. coramutata, Grun. 



Auricula punctata (p. 115) can scarcely be specifically 

 distinct from A. insecta. 



Auricula staurophora (p. 117) is no doubt tlie same form as 

 Amphora quadrata (Breb.), CI. 



Nitzschia duhia (p. 122) : too coarsely striate (strias 12-13 

 in 0"01 mm.) to be the species of W. Smith (striee about 23 in 

 0-01 mm.). 



Nitzschia valida (p. 127) : probably A', sigma. The true 

 N. valida occurs in warmer seas only. 



Campylodiscus parvulus (p. 132) = C. Thureti, Br^b. There 

 can scarcely be any doubt that C._parvulus, W. Sm.= C. Thu- 

 retij Breb., and that C. parvulus^ Van Heurck, Syn. 

 (Ixxvii. 2), represents another species akin to G. Lorenzianus^ 

 Grun. 



B. Notes hy C. Mereschkowsky. 

 Fragilaria striatula, Lyngb. (p. 23), 



has, according to Karsten, a single plate (he expresses, 

 however, some doubt about it). The var. calif ornica, Grun., 

 has four plates ; it seems most probable that the type also 

 possesses the same number of chromatophores. Also F. hya- 

 lina has four plates. I doubt whether F. crotonensis (A. M.- 

 Edvv.), Kitt. p. 24, has only one plate. 



Synedra sp. (Hennedyana ?) (p. 27) 



is doubtless nothing but CylindrotJieca gracilis (Breb.), 



Grun. See C. Mereschkowsky, "A List of Californian 



