250 Messrs. Sullivant and Wormley on the Strie of Diatoms, ° 
The above, including the second volume of Smith’s Synopsis, 
embraces about all the information on — relating pie 
subject of these papers, known to the wr 
The measurements of the larger cteion eR, the following 
cies were made on authenticated English ba "ih 
ures affixed to each species express the numbe 
strie in the ;,'5,th of an inch (001”), as demesne b ws; 
measurements accord very nearly with those in the ‘Synopsis, 
not differing more than might be expected in observations of 
‘this kind: besides it is well known that the striation of each 
ies varies within certain limits peculiar to the species. 
other eases, however, there are discrepancies between our mete 
urements and those in the Synopsis, too great to be accounted 
for in this manner. 
Nitzschia sigmoidea, 72 to 75; Ait Smith); (105, Harmsou 
and Sollitt).—N. obtusa, 54; (66, S.).—N. lana, 50; (56, S) 
N. linearis, 73.—Stauroneis ‘linearis, 65.—Cocconeis Thwaitest, 
54; (72, S). —Amphora membranacea hoop 58, valve 36; ° 
S.).—Cymbella cuspidata, 35; PA 8.).—C. Scotica, 4 45; ee 
—Navicula lanceolata, 40; (44, S.).—N. i 2 ; (42, 
ambigua, 38; (86, S. _—_N: sphzero hora, 40; 5 ar : 
Eas 6 ; (48, S). Se rhomboidele 70; (88, S.).—Pinnulana 
Johnsoni, 48; (56, 8.).—Fragillaria virescens, Bai (44, 8. oe 
Capucina, 40; (40, S.).—Colletonema vulgare, 72; (72, 8) 
eximium, 56; soe we —Achnanthidium coarctatum, 34; ut a 
~ 
Pleurosigia es 70; (85 S\a-¥ anguiat um, i 
(52, S.); (75, S.). Ses anse 
are n 
53 long 55 ne.) A cag to ah "Pfc a 3); (, 
H. 
long., 5.) 
ig sexi 5 tr., =P Tip long. ; (52 we 40 long. 8. (dott, 
:S). es} ss 
, 8.).—P. formosum, 36 tr., one set of be ae 
a the other 30; (86, S.).—P. decorum, 45 tr. 36 ore (63, 
—P. intermedium, 56; (65, S.)—P. Balticum, 365 
