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



N. Clutlietisis var. minuta Cl. 



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

 puncta, abbreviate around the central nodule, 15 in 0,01 mm. in the raiddle, 18 in 

 0,01 mm. in the ends. 



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

 Pl. II, fig. 22, """/,. 



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



The following varieties of N. Cluthensis are described: 



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

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



6. eiythrcea {N. erythrcea Grun. Verh. 1860 p. 539, Pl. III, fig. 17) with 10—12 

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



c. Finmarchica Grun. (in Cl. et GruN. Aret. Diat. p. 40, Pl. II, fig. 49) with 

 11 — 12 striee in 0,01 mm. and very small area. Length 0,022 — 0,024 mm. 



d. maculifera Cl. with 11 striaä in 0,01 mm. and tolerably large area. 



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



13. Navicula bicuspidata Cl. et Grun. 



Oblong; slightly constricted in the middle, apiculate. Stria; coarse, finely pun- 

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



Length 0,04 mm. Breadth 0.015 mm. 

 Pl. II, fig. 25, --A. 



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. Striaä coarse, 15 in 0,01 mm., very 

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

 where there is a transverse blank space. 



Length 0,04—0,06 mm. Breadth 0,005—0,008 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. Pinnidaria Cl. 

 (Cl. et Grun. Aret. Diat. p. 27) but is more convex and has closer striaj. 



15. Navicida Fromenterce 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, ""%. 

 Balearic Islets (F. Söderlund). 



