12), a west Australian creature of the size of a mouse, which may be regarded as representing by itself a sub-family (Tarsipediinae), characterized by the rudimentary teeth, the long and extensile tongue, and absence of a caecum.
All leeches are very extensile and can contract the body to a plump, pear-shaped form, or extend it to a long and worm-like shape.
Each palpacle is a tactile filament, very extensile, without accessory filaments or nematocysts.
By the absence of one pair of upper incisors, the small size of the cheek-teeth and the very extensile character of the lips.
The mouth is small and tubular, furnished with a long extensile tongue.