WMTISIf lr.S.MIDTACEJr:. 



Cells of medium size, narrow and elongate, 26-36 

 times longer than their diameter, straight or but 

 slightly curved, outer margin about oO of are, margins 

 almost parallel for about seven-eighths of the length, 

 slightly attenuated near the apices, which are capitate- 

 Irimcate; cell-wall smooth, colourless, yellow, or 

 reddish-brown; chloroplasts with a central row of 

 pyrenoids. 



Zygospore unknown. 



Length 200-489 /x; breadth 10-13/n; breadth of 

 apices 8'5-12*5 /z. 



SCOTLAND. Balmacarra, Ross (A. IT. IT// 



Var. fusiforme Turner. (PI. XX, fig. IS.) 



Cl. Scot [cum var. fusiforme Turn. Desm. Notes, 18915, p. .47 ; Roy & Biss. 

 Scott. Desm. 1894, p. 2-K), t, 4, f. !). 



Cells almost straight, decidedly fusiform. 

 Length 29o-4K> /A ; breadth 12' 5-1 o ^ ; breadth of 

 apices 9-11 '-5 /JL. 



SCOTLAND. Balmacarra, Ross (A. W. Wills). 



89. Closterium pusillum Hantzsch. 



Cl ixti'i-iinii pus'tlliim Hantzsch in Rabenh. Alg. Europ. LSMl, no. loos; 

 Rcinseh. Al^cnn. Frank. 1S(>7, p. IS"; Ealw-nh. Flor. Europ. Alg-ar. Ill, 

 isr.s, p. HT, ; I),. Tuni, Syll. Alg. ISSO. p. SL'O ; L'..y ^ liiss. Scott. Desm. 

 IS'.il., j>. IMS; Nordst. Index Desm. lsHi, p. :>]:;. 



Cl. pusUlinii ;i. tumor Eacib. Nonn. Desm. Polon. lSS."j, p. (J'5. 



Arthrodia jmalUu Knntx.c. ]{cvis. gen. plant. 1S<)1, p. SM4. 



Cells very small, subcylindrical, 4-7-;} times longer 

 than their diameter, slightly curved, outer margin l<> 

 ")0 of arc, inner margin slightly concave, very 

 gradually and gently attenuated to the apices, which 

 are obt usely or truncately rounded ; cell-wall smooth 

 and colourless; chloroplasts with about six ridges 

 and with one or two pyrenoids; terminal vacuoles 

 prominent, with one or two moving granules. 



/ygo^pore quadrate. 



Length 30-50 //. ; breadth 4-9 p. 



SCOTLAND. Achnasheen, Ross; Anchterless, Long- 



