BY G. I. PLAYFAIR. Ill 



Coenob. (cell. 8) diam. 40; cell. diam. 10, crass. 5 /x. 



Lismore(ll). Cum priori. 



Syn. Kirchn. aperta Einar Tailing, Svenska Bot. Tidskr., 1012, 

 p. 276. This form is somewhat like Selenoderma Malmeana 

 Bohlin, Ersten Regnellsehen Exp., i., p. 21, T.i., f. 31-35. I doubt 

 very much whether there is any difference between the two genera. 

 Cf. also Sorastrum hidentatum Reinseh, De Spec, generibusque, 

 T.i., f.D iv. K. lunaris var. contorta (Schm.), PI. iii., f 30, and 

 var. gracillima (Bohlin) also noted. 



BACILLARIE^. 



Genus Amphora Ehr. 



Amphora coff^ifohmis Ag. (PL iv., f.l). 

 Long. 27; lat. valv. 7; crass, frust. 12, ap. 6 /x. 

 Lismore(5,13). 



Syn. A. salina W. Sm. Strias very fine and faint, hardly dis- 

 cernible. 



Amphora veneta var. grossestuiata, n.var. (PI. iv., f.2, 3). 



Striae crassse 6-7 in 10 fx. 



Long. 32-75; lat. valv.11-16, ap.3-4; crass, frust. 12-16, ap.6-8/x. 



Lismore(12, 13, 17, 20, 21, 22) ; Kyogle (41). 



For the type, Cleve, Syn., ii., p. 118, gives long. 20-60, lat. 11-18, 

 striae 20 in 10/x. In the river, this form was in company with 

 Cocconema tumidum, and it was noticeable that the striae on both 

 were equal in number and of similar character. 



Genus Cocconema Ehr. 

 Cocconema tumidum Breb. (PL iv., f.4). 



Long. 70-90; lat. valv. 20-22, ap. 8-10 /x Strise 6 in 10 /x. 



Lismore(l, 2, 6, 8, 11, 12, 15, 18, 20). Casino (14). Kyogle 

 (41,45). 



Very common in the river. The boat-shaped frustule, rostrate- 

 truncate ends, and especially the diamond-shaped area round the 

 central nodule, define this form. 



