Land Slugs - eggs and development
Triboniophora graeffei [Fam. Athoracophoridae] showing clutch of eggs at the hatching stage. See small recently hatched juvenile slug at right of photo, and 'about to hatch' slugs in eggs. This eastern Australian slug is know and the Red Triangle Slug for obvious reasons. Photos: Bill Rudman.
The largest group of Land Snails, the Stylommatophora, with over 90 families, all have eggs which develop into small crawling young within the egg capsule. Without the loss of a swimming larval stage, they would have been unable to free themselves from their ancestral watery environment. Although not a Stylommotaphoran, Triboniophorus also has direct development. The Athoracophoridae are a southern family of terrestrial slugs found only in eastern Australia, New Zealand, New Caledonia,. New Guinea and Vanuatu.
Rudman, W.B., 2006 (June 14) Land Slugs - eggs and development. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/landslugs03