Species of Diatoms from Hongkong. 7 



mounted slide the margin appears of a fine blue colour. Length 

 of frustule -0040". 



Amphiprora chinensis, n. sp., Grev. PI. V. fig. 13. 



Front view transversely striated, oblong, rounded at the ends, 

 moderately constricted at the middle ; wings flatly convex ; 

 supplementary wings narrow, with a marginal row of dark 

 points ; connecting zone with a few narrow, ridge-like lines ; 

 striae minutely moniliform. 

 Hah. Hongkong Harbour; in material communicated by J. L. 

 Palmer, Esq. 



The frustules are sometimes twisted so as to throw a portion 

 of the wings out of focus ; and the disposition to twist seems 

 almost always to cause more or less undulation in the rib-like 

 lines of the middle portion. The whole surface is transversely 

 striated, and the striae of the wings are clearly, although ex- 

 tremely minutely, moniliform. The flatness of the wing-curves 

 gives a degree of parallelism to the general outline, which is 

 very characteristic. The supplementary wings follow the curve 

 of the primary ones in a somewhat less degree, and pass down 

 within the nodules, having the appearance of an elevated ridge, 

 the ridge-line marked with a row of minute dark spots (scarcely 

 puncta), caused possibly by the intersection of the striae. Length 

 of frustule •0040" and upwards. 



EXPLANATION OF PLATE V. 



Fig. 1. Frustule of Palmeria Hardmaniana : front view, magnified 100 

 diams., showing the lines of future fissiparous division. 



Fig. 2. The same, showing the valves. 



Fig. 3. The same, showing the valves and frustule in the process of divi- 

 sion. 



Fig. 4. Valve of the same, showing the radiating structure, magnified 

 150 diams. 



Fig. 5. Asterionella Synedrceformis, exhibiting two of the frustules and 

 the bases of others in situ. 



Fig. 6. Valve of the same. 



Fig. 7. Surirellu Palmeriana. 



Fig. 8. Cresswellia annulata : two frustules in situ, the valves of one of 

 them separating. 



Fig. 9. Hemiaulus chinensis : two frustules in situ. 



Fig. 10. Amphiprora lepida. 



Fig. 11. „ hyalina. 



Fig. 12. „ venusta. 



Fig. 13. „ chinensis. 



[All the figures are magnified 400 diameters, except figs. 1 to 3, which 

 are magnified 100, and tig. 4, which is magnified 150 diameters.] 



