Updated key to the species of the genus Cratera

1 Prostatic vesicle with an ovoid extrabulbar portion and an elongate intrabulbar portion....................... C. arucuia

- Prostatic vesicle with a single portion..................................................................... 2

2 Prostatic vesicle intrabulbar....................................................................... C. picuia

- Prostatic vesicle extrabulbar............................................................................. 3

3 Penis papilla projecting from the roof of the male atrium with a large intra-penial cavity..................... C. cuarassu

- Penis papilla projecting from the anterior portion of the male atrium............................................. 4

4 Dorsal color predominantly dark, without wide stripes of other colors............................................ 5

- Other color pattern.................................................................................... 9

5 Prostatic vesicle with proximal portion dorsally oriented............................................. C. obsidiana

- Prostatic vesicle with other morphology................................................................... 6

6 Dorsal margin yellow to reddish......................................................................... 7

- Dorsal margin dark.................................................................................... 8

7 Dorsal margin dark yellow and dorsal median dark yellow stripe......................................... C. tamoia

- Dorsal margin rust red, dorsum with conspicuous white halos over dark background........................... C. joia

8 Prostatic vesicle C-shaped, with proximal portion curved ventrally and posteriorly........................... C. crioula

- Almost straight prostatic vesicle............................................................. C. cryptolineata

9 Widening of the distal portion of the ejaculatory duct absent or inconspicuous................................ C. hina

- Widening of the distal portion of the ejaculatory duct conspicuous............................................. 10

10 Roof of male atrium not pierced by numerous cyanophil glands.................................... C. nigrimarginata

- Roof of the male atrium pierced by numerous cyanophil glands................................................ 11

11 Prostatic vesicle of irregular shape and very sinuous at its distal portion..................................... C. yara

- Prostatic vesicle straight or C-shaped, with less sinuous distal portion........................................... 12

12 Prostatic vesicle curved in a C or inverted U shape.......................................................... 13

- Prostatic vesicle straight or with proximal portion slightly ventrally oriented..................................... 16

13 Dorsum with a mottled gray pattern over a greenish background................................... C. viridimaculata

- Dorsum with a striped pattern.......................................................................... 14

14 Orange dorsum with two white bands bordered by irregular black stripes on each side.............. C. pseudovaginuloides

- Dorsum with yellow margins and two black lateral stripes or bands............................................. 15

15 Dorsum with black bands, wide, separated by white median band...................................... C. taxiarcha

- Dorsum with black bands separated by yellow or orange median band................................. C. anamariae

16 Wide orange band bordered by paramarginal black stripes.............................................. C. steffeni - Dorsal surface with yellow background covered by dark pigmentation sometimes forming more or less defined stripes.... 17

17 Dorsal surface with dark pigmentation forming two lateral rows of irregular spots and some scattered dots..................................................................................................... C. aureomaculata

- Dorsal surface with dark pigmentation more uniformly scattered or forming two lateral stripes and one median or two parame- dian bands with ill-defined margins................................................................. C. ochra