FIGURE 3. Camera-lucida drawing of specimen, with certain features (notably structures interpreted as extrabranchial atria) combined by reversal from the counterpart (Fig. 1c), to show interpretation.
From the following article:
Lower Cambrian vertebrates from south China
D-G. Shu, H-L. Luo, S. Conway Morris, X-L. Zhang, S-X. Hu, L. Chen, J. Han, M. Zhu, Y. Li and L-Z. Chen
Nature 402, 42-46(4 November 1999)
doi:10.1038/46965
Numbers 1–4 refer to gill pouches identified with reasonable certainty; ?A and ?B refer to more tentative identification of gill pouches, of which ?A is less certain than ?B.
