DIATOMACEiE FROM SPTTZBERGEN. 259 



on both sides so as to include a somewhat rhomboid area, 

 very different, indeed, from the outline of this same space in 

 Navicula didyma. This peculiarity appears in the speci- 

 mens I have obtained in various parts of Ireland, as also in 

 all the very numerous forms that came under observation 

 while examining these collections from Spitzbergen. In ad- 

 dition to this striking peculiarity, the character of the striae 

 differs from that of N. didyma, being greatly coarser than 

 they are in that species. I would suggest that the form 

 should be named Navicula Gregoriana. 



Over and above the forms included in the two foregoing 

 lists the following came under notice, which appear to me 

 not to have been hitherto described : 



Asterionella Cleviana, n. s., PI. VIII, fig. 6. — Length of 

 valve '0036 ; the lower end small and roundish ; the upper 

 end much larger and somcAvhat rhomboid in its outline ; 

 strise marginal, costate. Several specimens of this occurred, 

 always single, as might have been expected, so that I am not 

 quite certain that I have assigned the form to its proper 

 genus. 



Amphora Eatoniana, n. s,, PI. VIII, fig. 7. — Length of 

 valve "0056 ; breadth '0010 ; ends not produced ; broadly 

 rounded; dorsal margin strongly arched; ventral margin 

 slightly expanded ; expansion rounded ; median line strongly 

 marked, inclining inwards in an angle at the central nodule, 

 and gently curved towards the dorsal margin at either side. 

 Three longitudinal lines divide the valve into four com- 

 partments on the dorsal side of the median line. The two 

 nearest to the median line, like it, are doubly arched, and in 

 the same direction, except that they bend downwards at the 

 middle towards the central nodule. The third line is gently 

 arched nearly in the direction of the dorsal margin, and 

 anastomoses with the second some distance from the ends of 

 the latter. The striae are finely costate, and appear on all 

 the valve except the portion included between the second 

 and third longitudinal lines. There are also two small un- 

 striated spaces included between the ends of the first and 

 second longitudinal lines. This is a very beautiful and 

 peculiar form, to which, with much gratification, I give the 

 name of the gatherer. Rev. A. E. Eaton. 



Amphora Leighsmithiana, n. s., PI. VIII, fig. 8. — Length 

 of valve "0058 ; breadth "0008 ; dorsal margin slightly arched, 

 nearly linear in the middle ; ventral margin nearly linear, 

 slightly incurved at the middle ; ends attenuated ; median 

 line strongly developed, slightly arched towards the dorsal 

 margin ; central nodule small, but well defined. Striae 



