766 
PROCEEDINGS OF THE SOCIETY. 
*F. mutabilis (W. S.) Grun. 
*F. Harrisonii (W. S.) Grun. ( Staurosira E.) 
*Gomphonema braziliense Grun. 
*G. parvulum K. 
G. subclavatum Grun. 
* G. ventricosum Greg, var., doubtful. 
* Mastogloia Danseii Tliw. 
*31. Smithii Tliw. (The form /3 of the S. B. D.) 
Navicula ambigua E. 
N. ( Pinnularia ) appendiculata K. 
N. Bacillum E. 
N. biceps Greg, forma sta.ur oneif ’or mis Cl. (P. interrupta W. S.) 
N. binodis W. S. One specimen only seen. 
N. cryptocephala K. 
*N. cuspidata K. var. Shorter than the type, and with obtuser ends. 
Perhaps the var. danaica Grun. described by Cleve (S. N. D., p. 110). 
N. ( Diploneis ) interrupta K. (a B. W. species). 
*N. (Diploneis) elliptica K. 
*N. ( Pinnularia ) gibba W. S. 
*N. limosa K., and ditto var. gibberula Grun. 
*N. limosa var. alpina Cl. The ends of this little form are not so 
much rounded as Cleve’s var., bat it comes very near to it. 
*A T . ( Pinnularia ) mesolepta var. staur oneif ormis E. 
*N. radiosa K. 
*N. radiosa var. tenella (Breb.) Cl. 
N. ( Pinnularia ) subacuta E. 
N. ( Frustulia ) vulgaris (Thw.) Cl. {Coll, vulgare Thw.) 
*NitzscJiia amphibia Grun. 
N. amphioxys E. 
*N. ( Tryblionella ) angustata W. S. Longer, and with acuter ends than 
type. 
*N. Denticula Grun. {Denticula obtusa W. S.) 
N. fluminensis Grun. Narrower than type. Perhaps a form of 
N. paradoxa (W. S.) Grun. Scarce. 
N. marina Grun. A marine species ; one specimen seen. 
*N. Sigma W. S. var. A delicate form of N. Sigma which I have 
frequently observed in fresh or very slightly salt water. 
*N. Tryblionella Hantzsch var. Victorise Grun. Abundant. This is 
a short broad form of the Tryb. elegans W. S. 
Pleurosigma acuminatum K. (P. lacustre W. S.) One specimen seen. 
*P. Spencerii W, S. 
Schizostauron crucicula Grun. (Cl. N. & B. D., 1881, p. 16, pi. iii. 
44). This interesting little diatom has a bifid stauros, the ends of 
which are very divergent, so as to present the appearance of a St. 
Andrew’s cross. It is not rare in these slides, but for the most part 
obscured by the dirt and debris. I note, by Malt wood, three specimens, 
viz. Slide 1 fi Slide 2 f£, ff. 
*Stauroneis acuta W. S. 
S. Phoenicenteron E. 
S. pachycephala Cl. (N. & E. D., 1881, p. 15, pi. iii. 42). Described 
by Cleve as occurring in fresh, or slightly brackish water in S. Africa. 
