10 p. T. CLEVE, ON SOME NEW DIATOMS. 



N. Clutheiisis var. minuta Cl. 



Broadly oval, with rounded ends. Striae slightly radiant, composed of distinct 

 puncta, abbreviate around the central nodule, 15 in 0,01 nun. in the middle, 18 in 

 0,01 mm. in the ends. 



Length 0,03 mm. Breadth 0,014 mm. 

 PI. II, fig. 22, '""V,. 



Florida, Pensacola in a gathering, sent by Mr. Chr. Febiger. 



The following varieties of N. Cluthensis are described: 



a. genuina (Greg. Diat. of Clyde p. 6, PI. I, fig. 2) with 8 striag in 0,01 mm 

 and no area. Length 0,035 0,04 mm. 



b. eiythrcea (iV. erythrcea Grun. Verb. 1860 p. 539, PI. Ill, fig. 17) with 1012 

 stria; in 0,01 mm. and no area. Length 0,05 0,06 ram. 



f. FinmarcJiica Grun. (in Cl. et GruN. Arct. Diat. p. 40, PL II, fig. 49) with 

 11 12 striiB in 0,01 mm. and very small area. Length 0,0220,024 mm. 



d. macuUfera Cl. with 11 stria? in 0,01 mm. and tolerably large area. 



e. minuta Cl. with 15 18 stria? in 0,01 mm. and tolerably large area. 



13. Navicula hicuspidata Cl. et Grun. 



Oblong, slightly constricted in the middle, apiciilate. Stria' coarse, finely pun- 

 ctate, 6 in 0,01 mm., shortened around the middle. 



Length 0,04 ram. Breadth 0.015 ram. 

 PI. II, fig. 25, '"%. 



Mediterranean, Pithuisian Islands in a gathering sent by Prof. V. B. Wittrock. 



The nearest allied to this species seems to be Nav. directa Sm. The Nav. salva 

 A. ScHM. and Nav. opima Grun. have the terminal nodules at some distance from the 

 apices. 



14. Navicula mesoleia Cl. N. Sp. 



Very convex, linear with cuneate ends. Stria? coarse, 15 in 0,01 mm., very 

 slightly radiant, almost reaching the median line, absent from the raiddle of the valve, 

 where there is a transverse blank space. 



Length 0,040,06 mm. Breadth 0,0050,008 mm. 

 PL II, fig. 26 a and b, '""/,. 



Fresh water, Brazil, leg Dr. Warming. (Cl. et Moll. Diat. N:o 193.) 



This form has the appearance of some smaller varieties of N. Pinnularia Cl. 

 (Cl. et Grun. Arct. Diat. p. 27) but is more convex and has closer stria?. 



15. Navicula Fromentera' Cl. N. Sp. 



Small, elliptic. Stria? coarse, costate, 6 in 0,01 mm., reaching the median line, 

 but abbreviated around the nodule. 



Length 0,0375 mm. Breadth 0,0128 mm. 



PL II, fig. 24, '""y,. 

 Balearic Islets (F. Soderlund). 



