Letheobia

Wallach, Van, 2007, A review of East and Central African species of Letheobia Cope, revived from the synonymy of Rhinotyphlops Fitzinger, with descriptions of five new species (Serpentes: Typhlopidae), Zootaxa 1515, pp. 31-68 : 62-64

Key to East and Central African species of Letheobia based on external characters

1a. Nasal divided, with nostril pierced laterally; rostral less than half width of head................ L.uluguruensis

1b. Nasal semidivided, with nostril pierced ventrally; rostral more than half width of head ........................... 2

2a. Ocular much larger than preocular, in contact with labials; dorsum strongly pigmented ........................... 3

2b. Ocular smaller than preocular, separated from labials by subocular; dorsum weakly pigmented or colour- less .............................................................................................................................................................. 5

3a. Second supralabial overlaps preocular, which is half size of ocular; snout smoothly rounded .... L. obtusa

3b. Second supralabial does not overlap preocular, which is little smaller than ocular; snout bluntly or obtusely angular........................................................................................................................................... 4

4a. Snout bluntly angular, without a keratinized cutting edge; frontal larger than supraocular; middorsals 460 or more; Cameroon and western Central African Republic........................................................ L. decorosa

4b. Snout obtusely angular, with a keratinized cutting edge; frontal not larger than supraocular; middorsals 435 or fewer; southern Somalia....................................................................................... L. jubana sp. nov.

5a. Snout rounded in profile; ocular subequal to subocular .............................................................................. 6

5b. Snout with angular horizontal edge; ocular usually smaller than subocular ............................................. 10

6a. Scale rows 26-24-24; middorsals fewer than 360; Pemba Island................................. L. pembana sp. nov.

6b. Scale rows 24-22-22; middorsals more than 360 ........................................................................................ 7

7a. Middorsals fewer than 400; length/diameter ratio 62 or less; coastal Kenya and Tanzania.......................... ...................................................................................................................................... L. swahilica sp. nov.

7b. Middorsals more than 400; length/diameter ratio 62 or more ..................................................................... 8

8a. Supraocular larger than frontal; middorsals 418–433; Zanzibar Island ........................................ L. pallida

8b. Supraocular smaller than frontal; middorsals 427–487............................................................................... 9

9a. Supraocular in contact with rostral; nasal suture arising from first supralabial; southern Sudan................. ..................................................................................................................................... L. toritensis sp. nov.

9b. Supraocular separated from rostral; nasal suture arising from second supralabial; southwestern Ethiopia.. ......................................................................................................................................... L. largeni sp. nov.

10a. Second supralabial overlapping subocular .............................................................................................. 11

10b. No supralabial overlapping a superior head shield (rarely third supralabial overlaps subocular) ........... 13

11a. Preocular contacts supraocular; subocular contacts ocular; middorsals less than 515 ................... L. wittei

11b. Preocular contacts ocular; subocular contacts temporal; middorsals more than 540............................... 12

12a. Length/diameter ratio less than 85 ........................................................................................... L. rufescens

12b. Length/diameter ratio greater than 100 ......................................................................................... L. debilis

13a. Preocular more than half height of nasal; ocular separated from subocular by one or more temporals .. 14

13b. Preocular less than half height of nasal; ocular contacting subocular...................................................... 16

14a. Midbody scale rows 24; middorsals fewer than 625 ............................................................................... 15

14b. Midbody scale rows 22; middorsals more than 625 ..................................................................... L. gracilis

15a. Preocular contacts supraocular .................................................................................................... L. kibarae

15b. Preocular separated from supraocular by ocular......................................................................... L. graueri

16a. Midbody scale rows 24; rostral tapering posteriorly; colourless............................................ L. sudanensis

16b. Midbody scale rows 18; rostral parallel sided; dorsum pale brown ................................. L.lumbriciformis