Key to the species of Callulina

Callulina species are distinguished primarily in the field by the truncate to expanded toe- and fingertips. Parker’s (1934) initial distinction of breviciptid genera is based on the double condylar articulation between the urostyle and the sacral vertebra; a synapomorphy of Callulina and Spelaeophryne . Spelaeophryne and Callulina were distinguished by Parker (1934) on the basis of toe tip morphology.

1a. Fingers are expanded, the finger-tip width is greater than the width of the finger at the distal subarticular tubercle.. 2

1b. Fingers truncated, the finger-tip is not expanded beyond the width of the finger at the distal subarticular tubercle..... ............................................................................................................................................................ Callulina dawida

2a. The ratio between the widths of Finger 3 at the level of the distal subarticle tubercle relative to the width of its toe tip is always more than ¾. The distance between the tympanum and the posterior corner of the eye is equal to or greater than the tympanum diameter ....................................................................................................... Callulina kisiwamsitu

2b. The ratio between the widths of Finger 3 at the level of the distal subarticle tubercle relative to the width of its toe tip is less than ¾. The distance between the tympanum and the posterior corner of the eye is usually less than the tympanum diameter ......................................................................................................................................... Callulina kreffti