MICRASTERIAS. 121 



breadth of polar lobe 53-65 /a ; breadth of isthmus 

 25-26 /LI ; thickness 48 /<. 



ENGLAND. Mickle Fell, X. Yorks. 



Geogr. Distribution.- -Greenland. Galicia in Austria. 



18. Micrasterias Mahabuleshwarensis Hobson. 



Hicmsterias Mahabuleshivarensis Hobson in Quart. Journ. Micr. Sci. 1863, 

 p. 16S (with fig.), 169 ; Arch, in Quart. Journ. Micr. Sci. 1865, p. 255 ; 

 Eabenh. Flor. Europ. Alg. Ill, 1868, p. 196; Lund. Desm. Suec. 1871, 

 p. 15, t, 1, f. 6; Wolle, Desm. U.S. 1884. p. 112, t. 37, f. 10; Hansg. 

 Prodr. Alg-enfl. Bohni. 1888, p. 253 ; Nordst. Freshw. Alg. N. Zeal. 1888, 

 p. 31 ; De Toiii, Syll. Alg. 1889, p. 1122 ; Turn. Freshw. Alg. E. India, 

 1893, p. 95 ; Nordst. Index Desuiid. 1896, p. 163 ; West & GK S. West, 

 Freshw. Chlorophy. Koh Chang, 1901, p. 85. 



If. Americana forma Mahabuleshwarensis Mask. Note Micr. Americana, 

 1888, p. 9, t. 1, f. 8. 



Helierella MahabuleshiL'arensis Kuntze, Revis. gen. plant. 1891, p. 899. 



Cells moderately large, about 1-g- times longer than 

 broad, very deeply constricted, sinus open with an 

 acuminate apex; semicells 3-lobed, incision between 

 lateral lobes and polar lobe very wide; polar lobe large 

 and outstanding, lower half subquadrate, upper half 

 dilated, with the angles produced into diverging (some- 

 times almost horizontal), denticulate processes of con- 

 siderable (and variable) length, with a pair of accessory 

 denticulate processes disposed asymmetrically, one at 

 the front and one at the back near the base of each 

 lateral process, apical margin straight, slightly con- 

 vex, or slightly concave, generally with several large 

 granules (or short, acute spines) within the margin ; 

 lateral lobes deeply divided into two lobules by a wide 

 acute-angled incision, each lobule in the form of an 

 attenuated denticulate process ; apices of all the pro- 

 cesses tri- or quadridenticulate ; semicells in the middle 

 above the isthmus furnished with a small granulate or 

 denticulate protuberance, with a row of denticulations 

 within the lateral lobes (sometimes with several 

 scattered series) and within the lateral margins of the 

 polar lobe, these series generally extending to the basal 

 protuberance. Side view of semicell narrowly oblong- 

 ovate, with a small basal inflation on each side, apex 

 showing the asymmetrical disposition of the four pro- 



