Figure is written in a full name in the beginning of a sentence while it can be abbreviated in the middle or end of a sentence.
Figure X shows...
...is shown in Fig. X and...
...is shown (Fig. X).
An abbreviation of figure can be expressed as plural when Author refers to different figures.When Author refers to some figures in one figure, its abbreviation can be single.

...is shown (Figs. X, Y). / ...is shown (Figs. X and Y).
...is shown (Fig. Xa, b). / ...is shown (Fig. Xa and Xb)
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査読者が指摘するところではないので、校正段階で修正されるわけですが、万が一と思うと出版屋は焦りました。。。