164 MESSRS. W. WEST AND G. S. WEST ON 
31. Cosmarium anceps, Lund. Desm. Suec. p. 48, t. 3. f. 4. 
Forma paullo major, apicibus latioribus, angulis basalibus 
rotundatis et levissime productis. 
Long. 39 p ; lat. bas. semicell. 18 p; lat. apie. 15 p; lat. isthm. 
9:5 p. 
(PI. 8. fig. 12.) 
32. C. vncEUM, n. sp. (Pl. 9. figs. 8, 9.) 
C. parvum, duplo longius quam latius, profundissime con- 
strietum, sinu angusto-lineari ad extremum subampliato ; semi- 
cellulæ anguste truncato-pyramidatæ, lateribus retusis, angulis 
basalibus rectangularibus leviter rotundatis, angulis superioribus 
subrotundatis, apicibus leviter retusis; a vertice visæ oblongo- 
elliptiez ; a latere vise oblonge, apicibus rotundatis; membrana 
minute punctata. 
Long. 325-345 u; lat. bas. semicell. 15-16 u; lat. apic. 9'5- 
10:5 u; lat. isthm. 4 p; crass. 9:5 p. 
Compare with C. angustatum, Nordst. 
33. C. PAnvULUM, Bréb. in Mém. Soc. Sc. Nat. Cherb. iv. (1856) 
p- 133, t. 1. f. 18. 
A curious abnormal cell of this was seen. 
Long. semicell. 9:5 p; lat. 9:5 p. 
34. C. STRIATUM, Boldt, in Ofvers. Vet-Akad. Fórh. (1885) 
no. 2, p. 104, t. 5. f. 9. 
Long. 12:5 u; lat. 12 u; lat. isthm. 4°5 p; crass. 6 p. 
35. C. PACHYDERNUM, Lund. Desm. Suec. p. 39, t. 2. f. 15. 
Var. minus, Nordst. Norg. Desm. p. 18, i. 1. f. 7. 
Long. 56 p; lat. 48 p; lat. isthm. 18 p5 crass. 28 y. 
36. C. OBSOLETUM, Reinsch, Algenfl. Frank. p. 110, t. 9. f. 5. 
Long. 57-60 u; lat. 67-71 p; lat. isthm. 33-35 p; crass. 96 p- 
The specimens were often of a yellow or yellow-brown colour, 
and the basal angles of the semicells were thickened (not mamil- 
late); extending through this thickening was a marked conical 
pore which was broadest towards the interior of the Cosmarium. 
37. C. ASKENASYT, Schmi dle, in Hedwigia (1895), p. 904, t. A ET. 
Long. 142-158 p ; lat. 121-137 p; lat. isthm. 38-98 p; crass. 
5 p. 
7 
