338 Notes on New Species 



proaches much more nearly to Pinnularia stauroneiformis, 

 which apparently also occurs here. 



Fig. 33. This form I have failed in accurately deter- 

 mining. It bears considerable resemblance to Navicida 

 pnsi/la, Sm., in outline, but apparently has a large and dis- 

 tinct cingulum passing over and around the central nodule- 

 It also resembles a form doubtfully referred by Kiitzing to 

 Epithemia {Epithemia? cingulata, Kiitz., Bacillarien, Taf. 

 29, Fig. 66). Without the corresponding front view, it is 

 impossible to determine its nature, although I am disposed 

 to regard it as a true Navicida, of a new species. The 

 ^triae are distinct, radiant, curving slightly towards the 

 apices. The median nodule is also distinct. 



Figs. 34 and 35. Biddulphia trinacria, Bail., nov. sp. ? 

 I have already spoken of these forms under Fig. 25 as 

 probably varieties of Biddulphia Bailcyii, Smith. Fig. 35, 

 under the highest powers, can be resolved into circular 

 granules, decussately arranged, which are somewhat larger 

 on the connecting zone than on the valves. The processes 

 are also granulate to their extremities. 



Another form of this singular species has the valves and 

 connecting membrane reduced almost to a line, while 

 there are two long processes on each valve which curve 

 towards each other, and have between them one straight, 

 sharp spine, somewhat longer than the processes. 



Fig. 36. SiRiRELLA DUPLEX, Bail., nov. sp. Large, 

 oblong ; in front and lateral views panduriform ; ends 

 broadly rounded ; median band panduriform ; costae close, 

 distinct, and externally dilated. 



Hab. Para River. 



Fig. 37. SuRiRELLA . Probably a variety of 



Svrirclla decora, Ehr. Vide Mikrogeol. PI. XV. 



Figs. 38, 39, and 40. Campylodiscus collectus, L. 

 W. B., nov. sp. Large, saddle-shaped ; in front view un- 



