CVCLOPHORA. 



237 



Fig. 34. StictoJesmis Australia Grev. 



The Navicula which has given occasion for the creation of St. Australis 

 appears to be the N. Johnsonii or an allied form. 



Trachyneis Cleve (in litteris, 1893), a genus which corresponds with 

 our Aspera, and comprises N. aspera and Clepsyara. 



? ? Cyclophora Castr, 1878. 



Frustules with girdle face plicate, 

 showing in girdle view a semi-annulus 

 on the visible part of one valve. Frus- 

 tules in chains. 

 Jl 



C. tenuis Castr. (Atti. Ace. pont. 



N. Line, XXXI., and Diat. Chall., 18S6, p. 



53). 



Valve linear, very narrow, somewhat 

 F 'g- 35- Cyclophora n.sp. attenuate near the apices, which are 



obtuse rounded, bearing a large annulus at the median portion. Raphe 

 delicate, terminated by round nodules somewhat distant from the apices, 

 central nodule indistinctly surrounded by an elliptic annulus. Striae rect- 

 angular, very delicate, the transverse ones about 40 in 1 c.d.m. reaching to the 

 raphe. Girdle face rectangular. Sutural zone with numerous fine pleats, 

 bearing a semi-annulus on the margin of che valve. Length, 4 to 7 c.d.m. 



Marine. Ancona, Naples (Castr. !). Philippine Islands. 



The above figure represents the valve of a Cyclophora in a preparation 

 by Mr. Weissflog, from the Labuan Islands (Vega Expedition), which differs 

 considerably from C. tenuis by its length, median constriction and terminal 

 nodules, which are nearer the apices and by the absence of any central 

 nodule. Subsequent researches ought to show if this is really a new form, 

 which is probably the case. The entire characters of Cyclophora prove this 

 form to belong to the Navicular tribe. Count Castracane has ol late years 

 withdrawn the name of Cyclophora, and given to the above C. tenuis that 

 of Diatoma hyalina jorma Cyclophora, The pleats of the connecting zone 

 and the presence of a true raphe does not allow me to adopt Count 

 Castracane's latest opinion. I do not, however, believe that in the C. tenuis 



