बौधायन श्रौतसूत्रम् (कृष्ण यजुर्वेद तैत्तिरीय शाखा - सम्पूर्ण प्रश्न एवं श्रौत-याग कल्प सटीक)

/ᳵ:
Wait! In Bibliotheca Indica (Caland's BSS, etc.), they used the sign ᳵ (or ᳲ) to represent the anunāsika / pluta / ardhavisarga!
Actually, Unicode has:
U+1CF5 (VEDIC SIGN JIHVAMULIYA) ᳵ
U+1CF2 (VEDIC SIGN ARDHAVISARGA) ᳲ
U+1CE9..1CF1 for various Vedic anunasika signs.
Let's see what character it visually is:
It looks like a vertical stack of two crescents, or a butterfly-like sign: ᳵ (jihvamuliya/ardhavisarga).
Let's transcribe it faithfully as ᳵ.

Let's check line 17:
वास्तोष्पतिर्यदहुत्वा वास्तोष्पतीयं प्रयायाद्रुद्र एनं भूत्वानि-
Line 18:
रनूत्थाय हन्याद्वास्तोष्पतीयं जुहोति ' भागधेयेनैवैनᳵ शमयति '
Wait, at भूत्वानि- / रनूत्थाय:
"भूत्वानि-" at end of line 17.
"रनूत्थाय" at start of line 18.
Together: "भूत्वानिरनूत्थाय" -> "भूत्वा ऽनिरनूत्थ