1: flap connecting right eye-peduncle to exhalent siphon/epipodium.
2: flap connecting left eye-peduncle to inhalent siphon/epipodium.
Note; Fretter and Graham (1977) wrote that only the right eye-peduncle is connected to its adjacent neck lobe, but a connecting flap is visible on both peduncles in this image, and the left one is the most developed. (Because this image is from below, the animal’s left siphon is on the right of the frame.)
Image extracted from Gm24