104 BIOLOGY OF THE RICHMOND RIVER, 



together in one gathering ( 1 4 ), and are all intimately connected 

 biologically. Several mixed forms were seen. 



Cos. MAGNiFicuM var. Italicum Rac. 



Long. 118, lat. 96, ap. 30, isth. 78, crass. 60 /a. 



Lismore (12). 



In this form, there are no decided granules or scrobiculse in 

 the central portion of the semicells, granules only at the edge 

 and for a short distance inside. It is an intermediate form 

 between the type and Cos. Askenasyi, which is the smooth form 

 of Cos. tnagnificurti. The fact that this desmid, one of the largest 

 of the genus Cosmarium, was reported from Italy by Raciborski, 

 and from Sweden by Borge, after having been originally described 

 from New Zealand by Nordstedt, is not only interesting, but it 

 throws a strong sidelight on the question of the meaning of the 

 word species in the Desmidiacece. 



Var. FLUVIATILE, n.var. (PI. iii., f.l7), 



Semicellula3 truncato-conicee ; lateribus deplanatis ; apicibus 

 truncatis; angulis basalibus late-rotundatis: verrucis quadratis 

 totam marginem complentibus, juxta suturam dente singulo 

 utrinque munitse. Supra isthmum tumore nullo nee scrobiculis, 

 verrucis regulariter decussatim dispositis. 



Long. 132, lat. 94, ap. ca. 30, bas. 74, isth. 36 /x. 



Lismore (11). Cum forma typica. 



Cf. Nordstedt, Frw. Alg. N.Z., p.62, P1.6, f.l9. Cos. magni- 

 ficum, in common with most of Nordstedt's New Zealand types, 

 is found generally distributed in New South Wales. The short 

 spine at the basal angle seems to indicate that the verrucse may 

 be interchangeable with spines. Cf. Cos. suhhalteimi Schm., Ost- 

 Afrika ges. Desm., p. 25, T.ii., f.29, which is also a form of Cos. 

 magnijicum. 



CosMAKiUM DENTIFERUM Corda. (PI. iii., f.l8). 



Long. 106, lat. 114, isth. 30 /x. 



Lismore (18). Cf. VV. & G. S. West, Monog., iii., P1.78, f.I8. 

 Var suBLATUM (Nord.). (PL iii., f.22). 



Long. 110, lat. 110, isth. 28, bas. 94 /x. 



Lismore (18). Cf. Nordstedt, Frw. Alg. N.Z., PI. v., f.3. 



