Key to chromosomes of 11 cytoforms in the S. ceylonicum group in Thailand

1 Ring of Balbiani closer than double bubble to centromere.........................................................................2

- Double bubble closer than ring of Balbiani to centromere..........................................................................6

2 Blister and its heavy band reversed by inversion IIIS-1 (Fig. 3) ............................................. inthanonense

- Blister and its heavy band standard (Fig. 3)................................................................................................3

3 Double bubble and ring of Balbiani near end of IIS (Fig. 4A)....................................................................4

- Double bubble and ring of Balbiani about halfway between middle and end of IIS............................ sp. C

4 Parabalbiani and jagged group reversed (Fig. 5A) .............................................................. trangense n. sp.

- Parabalbiani and jagged group standard......................................................................................................5

5 IIIL with m2 marker distant from end (Fig. 6E)...................................................................... nr. asakoae 4

- IIIL with m2 marker near end (Fig. 6G) ............................................................................................ sheilae

6 Blister and its heavy band reversed by inversion IIIS-2 (Fig. 3) ........................................... curtatum n. sp.

- Blister and its heavy band standard (Fig. 3)................................................................................................7

7 Ring of Balbiani adjacent to double bubble................................................................................................8

- Ring of Balbiani and double bubble separated by 1.5 x width of ring of Balbiani (Fig. 4A) ....................... ......................................................................................................................................... doisaketense n. sp.

8 IIIL with polarity of m1 marker reversed....................................................................................................9

- IIIL with polarity of m1 marker standard..................................................................................................10

9 Inversion IIL-9 present (Fig. 5B)............................................................................................. nr. asakoae 3

- Inversion IIL-9 absent................................................................................................................ nr. sheilae 3

10 Inversion IIL-9 present (Fig. 5B).............................................................................................nr. asakoae 2

- Inversion IIL-9 absent ...................................................................................................................... asakoae