P. T. Cleve : The Diatoms of Finland. 51 



Cocconeis (Ehb.) Grun. 



C. Pediculus Ehb. — V. H. XXX, 28, 29. — C. Placentula 

 var. baltica Dannf. I, 1. 



Lad. 63, 66, 85, 86, Sinb. 83. 



Foss. B. 101, 102. 



C. Placentula Ehb. — V. H. XXX, 26, 27. 



Ab. 47, Al. 57, Lad. 86, Sb. 9, 18, Sinb. Ob. 83. 



Foss. Ob. 91. 



C. scutellum Ehb. — V. H. XXIX, 1, 2. 



Foss. B. 101. 



Achnaiithes Bory. 



A. longipes C. Ag. — V. H. XXVI, 13—16. 



Mb. Ab. 51, Sinf. Nyl. (Dannf.). 



Foss. B. 102. 



A. subsessilis Ehb. — V. H. XXVI, 21—24. 



Mb. Ab. 100, Sinb. 83. 



A. lanceolata (Breb.) Grun. — V. H. XXVII, 8—11. 



Sinf. (Dannf.) Ab. 48, 49, Sb., 1, 2, 7, 8, 10, 12, 18, Sinb. Ob. 

 ,83, Lt. 29, 31. 



Var. dubia Grun. — V. H. 12, 13. 



Ab. 48. 



Var. elliptica Gl. — Upper valve elliptic, 0,oi2 to 0,oi6 m. 

 m. in length and 0,0 o 7 to 0,0 9 m. m. in breadth, with 16 strife 

 in 0,oi m. m. The lower valve is not accuratelv known. 



P. Ill, f. 10 and 11. 



Ab. 48. 



A. Calcar CI. — Upper valve broadly elliptic, 0,oi2 in. m. 

 in length and 0,0 o 9 m. m. in breadth, with about 24 striae in 0,oi 

 m. m. It carries on the one side a horseshoe-like thickening, which 

 is prolonged on the other half of the valve into a spur-like pro- 

 jection. The lower valve is not known with certainty, but in 

 the same gathering, in which this species has been found, occurs 

 a valve of similar outline and size, the striae of which reach the 

 raphe and are 25 in 0,oi m. m. That valve, which has a greta 



