Here are some comparative photos of a number of Myrmechila (Chiloglottis) Orchids which were observed on Macquarie Pass today.
It appears that there are two species here - basically one with calli (glands) down to the very tip of the labellum, (Myrmechila formicifera) and one with calli (mostly) restricted to the rear (upper) half of the labellum (Myrmechila trapeziformis)
It is hard to make "hard and fast rules" for these plants, as one (the far right flower) has some tiny "bubbles" on the very tip of the labellum. However, when one looks at these 4 separate flowers, it is apparent that the two on the left have a different shape to the labellum from those on the right, which both clearly have a prominent central point to the labellum, which then curves in slightly, before pointing further out again, on either side.
These slight differences are more obvious if you click on the image to view it a full size. I should warn you that it was drizzling today, and these flowers have rain drops on their labellums, as well as the glands, but once warned, you will work that out easily.
Here are images of three "labellums" of Chiloglottis species. They show the obvious similarities, but the glands (pseudo-insects) are shaped differently having a general heart shape at the apex, whereas the Myrmechila have divergent heads, resembling "bug eyed" creatures. The differences between these plants and the closely related Chiloglottis Orchids is basically that these plants flower in winter and spring, and the others flower in summer and autumn. However, the lateral sepals (called "clubs") in these two species are widely divergent, in a more or less horizontal plane. By contrast, the clubs of the Chiloglottis Orchids photographed in the local area are held low down, under the labellum (and sometimes reflexed). See the various photos of the full flowers of Chiloglottis in this posting from March 2008.