116 BIOLOGY OF THE RICHMOND RIVER, 



Long. 40-57; lat. valv. 13-14, ap. 4 /x Striae 7 in 10 fx. 

 Lismore(l, 6, 13, 15, 17, 18, 20, 21, 22), both forms together. 



GoMPHONEMA CONSTRICTUM var. AUSTRALE, n.var, (Pl.iv.,f.23). 



Valvse parte superiore valde inflata, apiculo lato munitae; striis 

 binis alteris validioribus utrinque ad centralem nodulum prseditse. 



Long 50; lat. valv. cap. 16-18, constr. 10, centr. 13, bas. 5 /x. 



Lismore(l, 2, 6, 8), cum forma typica. 



Dimensions of the type are, here : — long. 40, lat. valv. cap. 12, 

 constr. 10, centr. 13, bas. 5 /x. 



GOMPHONEMA TRIANGULARE, n.Sp. (PI. iv., f.24). 



Yalvse minutse, triangulares, prope apices latissimse; lateribus 

 ad basin angustatam rapide convergentibus; apicibus depressis 

 subrostratis. 



Long. 24; lat. valv. 10, ap. 3 /x. 



Lismore( 1 ). Rarissime. 



Genus Achnanthes, Bory. 

 AcHNANTHES LANCEOLATA (Breb.) Grun. 

 Valvse elliptico-lanceolatae, apicibus late-rotundatis. 

 Long. 12-20; lat. valv. 7-8 /x. Striae 9 in 10 /x. 

 Valvse apicibus productis subrostratis, late-rotundatis. 

 Long. 20-25; lat. valv. 8-9, ap. 3-4 /x. Striae 9 in 10 /x, utrinque 

 20-24. 



Lismore(l, 6, 8, 17, 18, 20, 21, 22), both forms intermingled. 

 Cleve, Syn., ii., p. 192, gives striae 13-16 in 10 /x. 



Achnanthes calcar var. austkalis, n.var. (PI. iv., f.25-26). 



Valvae elliptico-lanceolatae, forma typica prae latitudine longi- 

 ores ; apicibus acuminatis interdum quam levissime rostratis. 

 Valva inferior linea media sola instructa. 



Long. 16-22; lat. valv. 7-8, ap. 2 fi. 



Lismore(6, 12, 13, 15, 17, 20). 



Var. PULCHERRIMA, n.var. (PL iv., f.27). 

 Valvae lanceolatae vel lineari-lanceolatae, longiores; apicibus 

 acute-rotundatis, interdum quam levissime rostratis. 

 Long. 24-40; lat. valv. 8-10, ap. 21 /x. 



