54 R- Gronblad, New Desmids. 



was obserwed. Vide also X. crist. var. spinuliferum West, 

 Mngr. IV pi. 110 f. 12. 



Hab. Keuru (C). — PI. 3 fig. 49—50. 



X. concinnum Arch.; West, Mngr. IV pi. 112 f. 10. 

 var. varians, nova var. Sinus plus minus apertus. Semi- 

 cellulae subtrapeziformes-sexangulatae lateribus inferioribus 

 longioribus, lateribus superioribus brevioribus; spinis non 

 geminatis, superioribus longioribus, inferioribus brevioribus 

 in angulis defixis, praeterea spinulis minutissimis nonnullis 

 irregulariter dispositis; papilla centralis abrupte truncato- 

 emarginata; a latere visae subcirculares; a vertice visae 

 regulariter ellipticae. Long. 10,6, lat. 10,6—11,3, isthm. 2,6— 

 3,9, crass, (c. papill.) 8 ft. [N:o 1275]. 



This variety is easily distinguished by the unpaired 

 spines at the angles, the small accessory spines and the 

 more subtrapeziform semicells. 



Hab. Esbo, (S) leg. C. Cz. PI. 7 fig. 71—73. 



Genus Arthrodesmus Ehr. 



A. curvatus Turn., E.-Ind. pi. 11 f. 33 and pi. 12 f. 

 2, 7, 13; Bernard, Desm. Prot. Java 1908 pi. 7 f. 196—197; 

 Bernard 1909 fig. 97; var. imatrensis, nova var. Spinis 

 convergentibus incurvatis, sed non recurvatis, semicellulis 

 plus depressis, isthmo angustiore introrsum acuto-subacuto, 

 cellulis minoribus. Long. 30, cum spin. lat. 57, sine sp. 

 lat. 38, isthm. 8— 11 /<. [N:o 1069]. 



This variety is more closely allied to A. curvatus than 

 to A. convergens: the open sinus, the very slightly and not 

 at all convex apex, the triangulate-cuneate semicells, all 

 these features are characteristic of A. curvatus. 



Hab. Raikala near Imatra Falls, (SE), leg. Hj. Hjelt. 

 PI. 3 fig. 51. 



A. glaucescens Wittr., Gotl. och 01. pi. 4 f. 11; West, 

 Madagascar p. 86 pi. 9 f. 37; Print z, Beitr. Norweg. PI. 3 

 f. 66—79. Long. 4,6, lat. 5,3 //. [N:o 1068]. 



