510 



OLEVE, DIATOMS. 



A. quaternatus Ehb. (Jan. Guan PI. I, A., fig. 8). 

 A. splendens (Shadb.) Ralfs (Halionyx undenarius Jan. Guan. 

 PL I, fig. 1). 



* Asteromphalus flabellatus Breb. (Grev. M. J. VII, p. 160^ 

 PI. VII, fig. 4 et 5). 



Melosira sulcata Ehb. 



M. (Endidya) oceanica Btw. (A. S. Atl. PL LXV, fig. 10, 12, 13). 



* Fodosira Argus Grun. (M. J. 1879, PL XXI, fig. 6). Dia- 

 meter 0,08 mm. Striae on the rim about 20 in 0,oi mm. The- 

 puncta which compose these striae are arranged in quincunx 

 as in many species of Pleurosigma. 



P. maculata W. Sm. (Lagerst. Bih. t. K. Sv. Vet. Ak. HandL 

 III, No 15, fig. 1). 



* P. Montagnei Kiitz. (Van Heurck Syn. PL LXXXIV, fig. 11). 



* P. amiigua Grun. (A. D. p. 118, M. J. 1879, PL XXI, fig. 7). 



* P. maxima (Kiitz.) Grun. (A. D. p. 118). Diam. 0,065 mm. 

 Umbilic. 0,oi mm. Rows of puncta 16 in 0,oi mm. near the- 

 umbilicus, 20 near the margin. 



VI. Diatoms from Bab-el-Mandeb. 



Between Aden and Bab-el-Mandeb were taken samples of 

 bottom-mud, which contained, sparsely, some diatoms, among 

 which I have determined the following: 



Amphora sebrina Jan (A. Schm. Atl. PL XXV, fig. 11). 



A. robusta Greg. (Diat. of CI. pag. 516, PL XIII, fig. 79). 



A. Proteus Greg. var. 



A. crassa Greg. (Diat. of CI. pag. 525, PL XIV, fig. 94). 



A. furcata Leuduger-Fortm. (Diat. de Ceylan pag. 20, PI. 

 I, fig. 11). 



A. mexicana A. Schm. (Atl. PL XXVII, fig. 47—48). 



A. cymhifera Greg. — Length of valve 0,o85 mm., breadth 

 0,011. Striae 8 in 0,oi mm. composed of distinct granules. 



Navicula aspera Ehb. 



N. directa W. Sm. — Length 0,ii mm. Breadth 0,oi3 mm. 

 Stri^ 6 in 0,oi mm. 



N. maxima Greg. var. Bleischii Jan (A. Schm. Atl. PL L,. 

 fig. 22—25) Length 0,i3 mm. Strise 17 in 0,oi mm. 



N. maxima Greg. var. umhilicata Grun. (A. Schm. Atl. PL 

 L, fig. 32—33) Length O.is mm. Striaj 12 in 0,oi mm. in the 

 middle, 15 in 0,oi mm. near the ends. 



