COSMAEIOI. 39 



EXGLAXD. Pilmoor, near Thirsk, X. Yorks ! 

 IRELAND. Creggan Lougli and Kylemore, Galway : 

 Georjr. Distribution.- -Madagascar. 



Yar. montanum Sclimidle. (PI. LXVIII, figs. 29-31.) 



C. Novae-Semlix Wille var. polonicum Eichler & Gutw. Xonn. spec, 



nov. 1894, p. 170, t. 5, f. 21. 

 C. Regnesi var. inontanum Sclimidle, Weit. Beitr. Algenfl. Eheineb. u. 



Schwarzwald. 1895 (April), p. 74, t. 1, f. 9 ^figure bad" ; Beitr. alp. Alo- 



1895, p. 389, t. 15, f. 11 ; West & G-. S. West, Alga-fl. Yorks. 1900, p. 89. 

 C.Pseudoregnesii West & G. S. West, Alg. Maclag. 1895 (Oct.), p. 59, t. 6, 



f. 42; Xotes Rec. Publ. Desm. 1896, p. 336. 

 C. montanum Sclimidle in Xuova Xotarisia 1897, p. 66; West G. S. West, 



Alg. S. England, 1897, p. 487. 

 C. montanum Sclimidle var. Pseudoregnesii (West) Borge, Siisswasser- 



algen Siid-Patagon. 1901, p. 22. 



Cells slio'htlv larger, often with a narrower isthmus ; 



v 



semicells with three protuberances, one central and one 



a little smaller within each lateral margin ; vertical 



. 



view with a conspicuous protuberance in the middle 

 on each side, and a smaller one on each side just below 

 each pole. 



Length 109-15'5/x; breadth lOl-lo'o p. ; breadth 

 of isthmus 4'6-6'5/x; thickness 5'4-7'7/x. 



EXGLAXD.- -Pilmoor, X. Yorks ! Eiccall Common, 

 E. Yorks ! Epping Forest, Essex ! 



Geogr. Distribution. Germany. Poland. Galicia. 

 Sweden. Madagascar. Patagonia. 



This varietv. which unfortunately received three different 



/ > ,' 



names much about the same time, is primarily distinguished 

 from the typical C. Regnesi by the three protuberances 011 

 each side of the vertical view. It is the largest variety of 

 C. Regnesi, and the semicells are almost invariably eight- 

 toothed. Although the extreme form of this variety is so 

 distinct as to have been regarded as a separate species, yet 

 all intermediate states exist between it and the type. The 

 extent to which the protuberances are developed vark-> 

 greatly, even in specimens from the same locality. In sonn- 

 examples they are very prominent and conspicuous, but in 

 others thev are scarcely discernible. Some of these inter- 



C< t,' 



mediate forms are figured on PL LXVIII, figs. 32-34. 



Note. The Desmid described as Euastrum crenulatum 



