176 P. T. CLEVE, SYNOPSIS OF TIIK XAVICULOID DIATOMS. 



Var. hengalensis Grun. (1875). — V. le.ss asymmetrical, almost boat-shaped. with straight 

 or slightly centrally gibbous ventral margin.s. End.s obtuse. L. 0,os to O.ii; B. 0,o24 to 0,o2t 

 mm. Median line slightly arciiate. Axial area linear, scarcely dilated around the central nodule. 

 Strise 7,5 (middle) to 9 (ends) in 0,01 mm., coarsely punctate; puncta 12 to 13 in 0,i)i mm. — 

 C. Ung. Grun. in A. S. Atl. IX f. 12, 13; LXXI f. 79. Kitton Linn. Soc. Bot. XX Pl. XLVIII 

 f. fi (1884). Ol. M. D. Nro 194. 



Fresh water: Bengal! Socotra (Kitton). 



C. aspcra is a very common species, easily recognized by its boat-sliaped ontline, its coarsely 

 punctate strife and always distinct area. It appears to be more closely akin to C. Ehrenhcrgii 

 than to the boat-,shaped G. lanceolata, C. Cisiula etc. It .seems que.stionable whether the var. crassa, 

 whieh I liave not seen, really belongs to C. aspcra. It may pos.sibly be more akin to C. Cisfula. 



* C. saliiia Pant. (1889). — V. boat-shaped, witli arcuate dorsal margin, straight ventral 

 margin and obtuse ends. L. 0,0585; B. 0,oi.3 mm. Median line arcuate. Axial area distinct linear, 

 slightly dilated around the central nodule. Strife 12,5 to 13 in 0, 01 mm. punctate. — Pant. II 

 p. 40 Pl. 1 f. 9. 



Brackish water: Hungary, fossil (Pant.). 



This species is not known to me, but seems, to judge from the fig. in Pantocsek's work to 

 be allied to G. aspera, from which it differs by smaller size and closer strife. 



60. C. tumida Bréb. (1849). — V. boat-shaped with slightlj' centralh^ gibbous ventral 

 margin. Ends rostrate-truncate. L. 0,05 to 0,i; B. 0,oi8 to 0,022 mm. Median line arcuate. 

 Axial area nai^row, linear, suddenly dilated around the central nodule to an orbicnlar or sub- 

 ({uadrate central area. A stigma with a fine iissure below the ceutralj nodule. Strite 8 or 9 

 (middle) to 10 or 12 (ends) in 0, 01 mm., radiate, towards the ends almost parallel, distinctly 

 punctate; puncta about 20 in 0, 01 mm. — Goccon. tumidmn Bréb. in Ktltz Sp. Alg. p. (50. Gy. 

 tum. V. H. Syn. p. 64 Pl. II f. 10. Cocc. gibhum A. S. Probst. f. 17. Gy. sfomatopJiora Grun. in 

 A. S. Atl. X f. 28 to 30. Goccon. stomat. Grun. A. D. p. 26. 



Fresh water: Sweden (Westergötland, Göteborg)! Holstein (V. H. T.), Belgium (V. H.), 

 Germany! France! Mouth of Jenissey! Japan! Bengal! New Zealand! Australia, Victoria! Ame- 

 rica (Illinois, California)! 



Var. horealis Grun. (1880). — Ends obliquely truncate, not rostrate. Strife 8 in 0,oi mm. 

 — Gocc. stomat. var. horealis Grun. A. D. p. 26. 



Fresh water: Sweden (Grun.), Niagara Falls! 



Var. gihha Grun. (1880). — Dorsal margin with 3 to 4 undulations. StrifB 8 to 9 in 0, 01 

 mm. — Goccon. stomat. var. gibba Grun. A. D. p. 26. 



Var. fossilis Grun. (1880). — V. with less rostrate and more rounded ends. Stigma with 

 shorter fissure than in the type. — Goccon. stomnf. var. fossilis Grun. A. D. p. 26. 



Fresh water: Habichtswald, fossil (Grun.). 



61. C. aii.stralica A. S. (1875). — V. boat-shaped with centrall_y gibbous ventral margin 

 and truncate or rounded obtuse ends. L. 0,i to 0,14; B. 0,02g to 0,o3 mm. Median line arcuate. 

 Axial area linear, suddenly dilated around the central nodule to an orbicixlar space. A stigma 

 with a distinct fissure below the central nodule. Stri;i' 7 (middle) to 9 (ends) in 0, 01 mm. slightly 

 radiate in the middle, parallel at the ends, coarsely punctate; puncta about 13 in 0, 01 mm. — 

 Cocc. austr. A. S, Atl. X f. 34, 35. Cl. M. D. N:o 295. 



Fresh water: Australia! New Zealand! 



62. C. puiictifera Cu. N. Sp. — V. boat-shaped, with truncate ends. L. O, ].•?; B. 0,o2 mm 

 Median line arcuate; terminal fis.sures reflexed. Axial area linear, suddenly dilated to an orbicular 

 central area. Stigma in the middle of the central nodule, without distinct fissure. Stritu 8 in 0,o i 



