370 



Tliis processus antihelicis becomes the "tragoid projection"; 

 "metatragus," or "supratragus" of authors. A true tragus 

 cannot be said to be present, but a small antitragus is 

 developed on the ventral (caudal) border of the helix margin. 

 The single processus antihelicis which is present in Trichosurus 

 is a purely functional structure which fits into the conchal 

 orifice of the auditory meatus when the auricle is folded down- 

 wards and forwards as in sleep. As such the process may be 

 described as a meatal operculum. 



Mantis. — The digital formula of young specimens is 

 either 3>4>2>5>1, or 3 = 4>2>5>1 (see fig. 9). The 

 classical formula 4>>3>'2>5>>1 is not seen in young ex- 

 amples, and it is by no means invariable in the adult. Claws 



Fig. 10. 



Left pes, plantar aspect. 



32 mm. embryo (from 



Specimen male A, Perth 



Museum). 



Fig. 11. 



Left pes from the plantar 



aspect. 45 mm. stage 



(from embryo Specimen 



male E, Perth Museum). 



are developed at the 32 mm. stage upon all the digits. Upon 

 the dorsal surface the hair is continued to the ends of the 

 ungual phalanges, the hair having a distal and an ulnar 

 trend. 



Apical pads are well developed. Interdigital pad I fuses 

 early with the thenar pad. The second interdigital pad is 

 displaced considerably towards the radial side by the very 

 large third interdigital pad, which occupies in most specimens 

 the palmar surface opposite digits 3 and 4. In the adult this 



