BY G. I. PLAYFAIR, 167 



Cl. cingulum, n.sp. (T.ii. f.7). 



CI. parvum, magis curvatum, filiforme, diametro circa 18 plo. 

 loiigius, lateribus parallelis, apiciV>us subacutis. 



Long. 90; lat. 5; alt. 30fi. 



Moura, in running water. 



In outline the nearest to this form is Cl. Cynthia var. curva- 

 tissimum West, (Scott, plankt., T. 14, f.3) with which it agrees 

 in length; but that species is striolate and 2.^ times as broad. 

 Cl. cingulum might be arranged with Cl. Jenneri Ralfs, and 

 Cl. calosporuin Wittr., especially var. /3 Brasiliense Burges., 

 (Desm. C. Braz.,T.2, f.5). 



Cl. cancek, n.sp. (T.ii. f.l6). 



Cl. minimum, canceriforme, subcirculare diametro tantum duplo 

 longius; dorso maxims convexum fere conicum; ventre concavum. 

 Semicellulae e sutura ad apices rapidissime attenuatae, apicibus 

 acutis pauUo incurvis et in rostra brevia setacea porrectis. 

 Membrana laevis. 



Long. 46; lat. 22; alt. 48)u. 



Murray's Lagoon, Collector. 



I know of no other species with which this form can be classed, 

 but cf. Cl. cu. spiel atum Bail., in Ralfs, T.35, f. 11. 



?Cl naviculoideum, n.sp. (T.ii. f.9). 



Cl. minutissimum, rectum, fusiforme, diametro circa 15 plo. 

 longius, apicibus acutissimis in rostra brevia setacea porrectis. 

 Membrana glabra. 



Long. 75-84; lat. 5-6/x. 



Murray's Lagoon, Collector. 



There is some doubt in my mind as to whether this is not the 

 diatom Nitzschia acicularis Smith, in Br. Diats. q.v.; no size 

 given. The disposition of the endochrome with a central clear 

 space makes it look like a Closterium. 



