Fig. 2 in A fold in the visor: formation of the bivalved shell in Berthelinia singaporensis Jensen, 2015 (Gastropoda: Heterobranchia: Sacoglossa), with notes on spawning and development

Fig. 2. Early development of Berthelinia singaporensis embryos. A, uncleaved eggs; B, 2-cell stage; C, 2–4-cell stages (1 h); D, 4-cell stage (1 h 20 min); E, 8-cell stage (3 h); F, multi-cell stage (6 h); G, blastula (22 h); H, early gastrula (23 h). Times in parentheses are after first cell division. In E and F, the spiral cleavage pattern is distinct.