COSMARIUM. 153 



Euastrum (Cosmarium) Cucumis Nag-. Gatt. einz. Alg. 18-49, p. 114. 

 Didymidium (Cosmarium) Cucumis Reinsch, Algenfl. Frank. 1867, p. 108. 

 Cosmarium Cucumis a. typicum Klebs, Desni. Ostprenss, 1879, p. 30, t. 3, 



f. 11, 12, 15. 

 Cosmaridium Cucumis Gay, Monogr. loc. Conj. 1884, p. 78, t. 2, f. 19; 



Hansg. Prodr. Algenfl. Bohm. 1888, p. 190. 



Co&marium Cucinnis 2. anglica Racib. Nonn. Desm. Polon. 1885, p. 70. 

 Pleurotaeniopsis Cucumis Lagerh. Algol. Bidr. 1887, p. 197. 



Cells large, 1-J-lf times as long as broad, deeply 

 constricted, sinus narrowly linear with a slightly dilated 

 extremity ; semicells semi-elliptic or widely truncate- 

 ovate from a broad base, both inferior and superior 

 angles rounded, apex rounded or sometimes slightly 

 truncate. Side view of seniicell obtusely ovate. 

 Vertical view broadly elliptic or elliptic-oblong, ratio 

 of axes about 1 : I'o. Cell- wall smooth. Chloroplasts 

 6 or 8 in each semicell, forming parietal, irregular 

 bands extending from base to apex, and each contain- 

 ing several pyrenoids. 



Zygospore unknown. 



Length 62-102 n; breadth 34-56 ^; breadth of 

 isthmus 20-38 /u ; thickness 27-38 p. 



ENGLAND. Cumberland ! Westmoreland (up to 

 2,400 ft.) ! (Ralfs). W., X., and E. Yorks ! Lanca- 

 shire! Essex! Oxfordshire! Warwick (Wills). 

 Gloucester (Ralfs). Surrey! Sussex (Balfs). Hants 

 (Bennett). Devon (Bennett). Cornwall ! 



WALES. Snowdon ! , Capel Curig ! (Cooke $ Wills), 

 Llyn Idwal ! , Llyn Ogwen ! , Bethesda ! , Llyn-an- 

 af on ! , Moelfre ! , and Yr Orsedd ! , Carnarvonshire. 



SCOTLAND. General! (Roy fy Bissett). Outer Heb- 

 rides ! Orkneys ! Shetlands ! 



IRELAND.- -Donegal ! Gralway ! Kerry ! Dublin 

 and Wicklow ! (Archer). Down ! 



Geogr. Distribution.- -France. Germany. Switzer- 

 land. Austria and Galicia. Poland. Hungary. Italy. 

 Portugal. Norway. Sweden. Denmark. Bornholm. 

 Finland. N. and S. Russia. Greenland. Spitzbergen. 

 Nova Zembla. Siberia. Iceland. Faeroes. Azores. 

 Burmah. Porto Rico. Brazil. Uruguay. Patagonia. 



C. Cucumis is somewhat variable both in size and in its 



