348 Notes on New Species 



Figs. A, B. Amphora obtecta, Bail., nov. sp. Frus- 

 tules in front view barrel-shaped, with straight, truncated 

 ends ; in lateral view linear-oblong, with concave venter 

 and convex dorsum ; outer portions of valves canoe-shaped, 

 nodules wanting or obscure ; whole frustule covered with 

 close, transverse stria?, which in front view intersect fine 

 longitudinal lines or folds in the connecting membrane, 

 giving the shell the appearance of being woven over. 



Hab. Lat. 0° 19' 05'' N., Long. 45° 43' 36" W. 



This species has the general appearance of Amphora 

 ovalis, but is somewhat larger, and may be distinguished 

 by the woven-like appearance of its striEB. 



Fig. C. Amphipentas obtusa. Bail., nov. sp. Sides 

 five, concave ; angles conical ; lateral surfaces slightly 

 concave, minutely granulated ; connecting membrane punc- 

 tate in parallel vertical rows. Differs from Amphipentas 

 flexiwsa, B., MSS. in the sides being concave instead of 

 gibbous. 



Hab. Lat. 0° 19' 05" N., Long. 45° 43' 36" W. 



This differs from Amphitetras only in the number of 

 sides, and may be considered as an additional instance of 

 their variability. The two preceding forms occur together. 



Cyclotella ? PULCHELLA, L. W. B., uov. sp. Disc 

 small, with a central umbo, from near the base of which 

 radiate (16) dilating styliform rays, which end upon the 

 margin in large granules. 



Hab. Lat. 1° 01' 29" N., Long. 46° 17' 46" W. 



This species, which occurs together with a beautiful 

 form, doubtfully referred to Sijnedra fitlg-ens by my father, 

 I have not been able to identify. There is, however, a 

 species of Cyclotella occurring in the Para, which may be a 

 variety of this species, and well deserves the above name. 

 It is of tiic same size as the present form, but from the great 

 difficulty of removing its carbonaceous matter frequently 

 appears opaque. I have one specimen in wliich there are 



