KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 26. N:o 2. 159 



„^ j Axial area indistinct C. gracilis Ehb. 



" ' I — — distinct, linear C. yarrensis A. S. 



^j, I Valve subclavate C. Beccarii Gkun. 



I — not clavate 23. 



Q., j Axial area broad C. aspera Ehb. 



— narrow or indistinrt 94. 



{ 



24. I 



Ventral and dorsal margins parallel C. Bofelhcs Lägst. 



— — — — not — 25. 



5>ri 



I Obtuse or truncate 26. 



\ Acute 31. 



Stria delicate C. delicatula Kvtz. 



97 



26. ■{ 



— coarse . 



Terminal fissnres straight C. helvetica KtJTZ. 



"''■ '' reflexed 28. 



Q j Stris coarsely punctate C. CisHda var. 



i 



I Stria 



- {t 



finely punctate 29. 



aboat 0,04 mm 30. 



about 0,12 mm C. lanceolata Ehb 



j Median lina almost straight C. parva W. Sm 



' \ — ■ — arcuate C. affinis Kt'TZ 



„.. J Median strise radiate .■'.•'.:.'>;!.::-; .i. I > C. pusilla Grun. 



{' 



not — • ., 32. 



I Strongly as3'mmetrical ' . . .' . . .". . . C. Icevis N.a;GELi. 



{ Sligbtly — C. rupicola Gei^n. 



Ends capitate 34. 



, — rostrate •.. ,. .•n; 37. 



' apiculate ..,....-.:; 46. 



not protracted i: i. '; .ii:r.-; . >..i. :l . ...i, .... 47. 



„ . , Striae very fine C. microcephala GsnN. 



distinct 35. 



Axial and central areas indistinct 36. 



— — — — distinct C. naviculiforniis Aueksw 



„^ f Valve almost symmetrical C. angusfata W. Sm. 



35. I 



I Stria 



I — decidedly asymmetrical C. amphicephala N.ä;GELi. 



{ 



„ ,' Median ventral strise ending with isolated pnneta C. tnmidiila Grun. 



— — not — — — 38. 



„„ . Central area small or indistinct 39. 



— orbicular 45. 



.,^ J L. O.oä to 0.0:> mm 40. 



\h. 0,07 mm. or more 42. 



.„ j L. abont 0,02.5 mm C. obtusiiiscula Grun. 



\ L. about 0,os mm 4L 



j Median striae about 9 in 0,oi mm C. lata Grun. 



' \ — — — 12 — C. spmria Cl. 



,g i Valve stout 44. 



"' \ — narrow 43. 



,„ f Striae 11 in 0,ni mm C. Stodderi Cl. 



' ' 1 — 17 — — C. ampMoxys Grun. 



Ends broad C. Cucumis A. S. 



not very broad C. Ehrenhergii KuTZ. 



.. I Small C. hyhrida Grun. 



1 Large C. heteropleura Ehb. 



... I Valve with nndulated margins C. Schmidfii Grun. ' 



' \ — — non — — C. ciispidata KtJTZ. 



._ I Ends obtuse 48. 



\ — acute 59. 



.„ I Valve linear 49. 



\ — lanceolate 51. 



44. I 



' C. conifera Br. and Héeib. 



