168 I". T. CLEVE, SYNOPSIS OF THE NAVIOULOin DTATOMS. 



p. fi8 Pl. LIV f. 345. A. S. Atl. X f. ()4 to 69; LXXI f. (i to 9. V. H. Syn. p. 65 Pl. III f. 9 

 to 11. CymheUa Encyonema Heib. Coiisp. p. 110 (lH6;-5). Encyonnini wc^avwirw Wartm. K.abii. Alg. 

 Eur. N:o 1248 (1862). 



Fresh or slightly braekish water: Sweden (Grulf of Bothnia, from Westerhotten to Roslagen; 

 Lake Mälaren)! Finland (Åbo, Ladoga)! England! Belgium (V. H.), France! Switzerland (Brun), 

 fTermany! Hnngary (Plattensee, Grun.), Italy (St. Fiora. foss.). 



36. C. (Encyonema?) inelegans Cl. N. Sp. — V. boat-sbaped, witb arcuate dor.^al margin, 

 straight or slightly connave ventral margin, and biYiad, roniided, soniewbat reflexed ends. L. U,i)5r) 

 to (),0fi5; B. 0,02 mm. Median line parallel to tlie ventral mai'gin, very excentric. Terminal 

 fissures eomma-like; terminal pores near the ends. Axial area linear, rather broad. Stria' oii the 

 dorsal side 10 (middle) to 12 (ends) sliglitly radiate; stria- on the ventral side s in O.oi mm., 

 radiate in the middle, parallel in the ends, coarsely pnnctate; pnncta 17 to 18 in o.ui mm. — 

 Pl. V f. 1. 



Fresh water: Fall River, Oregon, foss. (Grove Coll.)! 



37. C. (Encyonema) Triangiihim Ehb. (1845). — V. broad, asymmetrical, lanceolate with 

 acnte ends. Ij. 0,04 to 0,o.'j; B. 0, 02 mm. Median line straight, dividing the valve inte a ventral 

 part half as broad as the dorsal. Terminal fissnres in the ends of the valve. Axial area very 

 naiTow; central area small or indistinct. Strite 9 to 11 in 0,i)i mm. almost parallel or .slightly 

 radiate in the ends, coarsely pnnctate; pnncta about 10 in 0, 01 mm. — Gloeoiieiiin Irianyiihini 

 Ehb. Abh. 1845 p. 77. M. G-. XXXV A. 7 f. 10. Enryov. Trianc/. KuTz. Sp. Alg. p. 62. A. S. 

 Atl. X f. 54; LXXI f. 10. 



Fresh water: North America, New York and Pensacola (Atl.), Michigan, Dakota and Löst 

 Spring Ranch Oalif. ! Tasmania, Campbell Town, fossil! 



38. C (Encyonema) tnrgida Greg. (1856). — V. Innate, with .strongly arenate dorsal, cen- 

 trally gibbons ventral mai-gin, and acnte ends. L. 0,or, to 0, 10; B. 0, 012 to 0,023 mm. Median 

 line straight, dividing the valve into a ventral part of about half the width of the dorsal. Ter- 

 minal iissn]'es in the ends, comma-like, turned downwards. Axial area distinct, linear, scarcely 

 dilated in the middle. Stria- 7 to 9 in 0, 01 mm., radiate in the middle and, on the dorsal side, 

 at the ends, parallel or convergent at the ends on the ventral side, pnnctate; pnncta 13 to 18 in 

 0,01 mm. — Greg. M. .1. IV p. 5 Pl. 1 f. 18. Enrynn. tury. A. S. Atl. X f 49 to 53. V. H. Syn. 

 p. 65 Pl. III f. 12. 



Fresh water: Sweden! Finland! Mouth of Jenissey! Scotland (Greg.), East Indies! Java! 

 Anstralia (Murray River)! Tasmania! New Zealand! North America (California, Mexico)! Guate- 

 mala! Ecuador! Argentina! 



This species is very variable and graduates into the folloA\ing. TJie largest and most t}'- 

 pical specimens occi;r in California, Mexico and Ecuador. Enropean specimens are smaller and 

 can only with difRciilty l)e distinguished from the following species. 



39. C. (Encyonema) ventricosa KCitz. (1834). — V. Innate, with straight or centrally 

 gibbons ventral margin and subacnte ends, usnally tnrned downwards, L, O.ui.^ to O.oar. ; B. 0. 007 

 to 0,011 mm. Median line approximate to the ventral margin. Terminal nodnles and tissnres at 

 the ends of the valve. Axial area very narrow or indistinct. Stria' 10 to 16 inO.m mm, slightly 

 radiate, finely pnnctate. Frnstnles enclosed in branched mncous tubes. — Friishilin rrtttricosa K€tz. 

 Syn, p. 11 f. 7. (Jymh. rev. Bac. p, 80 Pl, VI f. 16. Encynn. rnitrir. V. H, Syn, p, ()6 Pl. III fig. 15 

 to 17, 19. Enryon. prostratum KiJTZ. Bac. p. 82 Pl, XXV f. 7 (1844). Encynn. c(rsj)itonum KVit. 

 Sp. Alg, p. 61 (1849). W. Sm. B, D, II p, 68 Pl, LV f, 346, V. H. Syn, p. 65 Pl. III f. 14; Suppl. 

 A f. 3. A. S. Atl. X f 57, 58; LXXI f. 11, 12. Evcyon. Amr.vrnhlii H.\bh. Sitssw. D. p. 24 Pl. VII 

 f. 2 (1853). CymheUa moruhifa W, Sm, B, I). I Pl. II i. 23. Vywh. affiuis rar. .<!rmieircnlaris 

 Lägst. Spitsb. 1). p. 43 Pl. II f. 20. Cocconemu Lnnula Ehb, Am, Pl 1: 1, f. 15 (1843), Encyon. 



