The framing structure of the whole system: Airāvata = the northern belt, Jaradgava = the middle, Vaiśvānara = the southern; each contains three vīthīs, three nakṣatras apiece, 27 in all. This is what makes Viṣṇu P. 2.8.85 coherent — the Pitṛyāṇa can be both 'south of Ajavīthī' and 'outside the Vaiśvānara path' because Ajavīthī is a sub-road of the Vaiśvānara belt. Vaiśvānara-patha is thus a real, textually attested Purāṇic sky-region name.
ऐरावत / जरद्गव / वैश्वानर (मार्गाः) Airāvata / Jaradgava / Vaiśvānara (the three mārgas)
the three great celestial belts — northern, middle, southern · — · the three latitude-bands of the ecliptic, each subdivided into three vīthīs
Attestations
Transcribed from the Devanagari OCR of the printed edition at shloka_source_url (Achyuta Nand Jha ed., vol. 1) and checked word-for-word against two further independent scans of two different printed editions of the same commentary — Krishna Chandra Dvivedi's (https://archive.org/download/brihatsamhitawithbhattotpalavivrittipartidr.krishnachandradvivedi/Brihat%20Samhita%20%20with%20Bhattotpala%20Vivritti%20Part%20I%20-%20Dr.%20Krishna%20Chandra%20Dvivedi_djvu.txt) and A.V. Tripathi's (https://archive.org/download/JiUm_brihat-samhita-part-1-of-varaha-mihira-by-avadh-bihari-tripathi-saraswati-bhavan-granthamala/Brihat%20Samhita%20Part%201%20of%20Varaha%20Mihira%20by%20Avadh%20Bihari%20Tripathi%20-%20Saraswati%20Bhavan%20Granthamala_djvu.txt). Only glyph-level OCR artifacts that all three scans show to be artifacts (e.g. OCR रद्वव for रद्गव, श्व for श्च) have been normalised; every substantive reading is as scanned, and the two places where the scans genuinely differ are flagged in identification_notes. The two halves are from two places in ch. 9 (the chapter opening and the commentary on v. 22), joined here by ellipsis. The Samāsa-saṃhitā line भरणीरौद्रमघाऽनिलशक्रधनिष्ठादिसम्प्रवृत्तेषु is a COMPOSITE of two damaged scans and is not verbatim from any single one: Krishna Chandra Dvivedi's reads भरणीरोद्रमघाऽनिटशक्रधनिप्ठादिसम्प्रवृत्तेषु, Achyuta Nand Jha's भरणीरीद्रमघाऽनिलशक्रधनिष्ठादिसम्मवृत्तेषु; each supplies exactly what the other loses. Flagged as a reconstruction. Also, the words ज्येष्ठाद्ये द्वे पञ्चनक्षत्रे in the Parāśara maṇḍala passage follow A.V. Tripathi's scan (ज्येष्ठादये दे); Achyuta Nand Jha's reads ज्येष्ठाय द्वे and Krishna Chandra Dvivedi's ज्येष्ठा द्वे.
VARIANT NAME-SET, NEW TO THE DATABASE. The database records the three mārgas only under the Purāṇic names Airāvata / Jaradgava / Vaiśvānara (Matsya 124.52). Utpala opens his commentary on Bṛhat Saṃhitā ch. 9 with a different trio: 'its nine vīthīs, three mārgas — northern, middle and southern — are the three mārga-divisions Vāta, Vyāḍa and Vaiśvānara; and there are six maṇḍalas.' Vyāḍa means 'serpent' (so Krishna Chandra Dvivedi's editorial footnote ad loc., which cross-refers to Parāśara's words in the ṭīkā on 9.22), i.e. Vyāḍa is a synonym of Nāga. Utpala's source is the Parāśara passage he quotes on BS 9.22, given as the shloka here: there Parāśara applies Vāta, Vyāḍa-mārga and Vaiśvānara to Venus's six maṇḍalas rather than to the vīthī-triads, so the two systems have been conflated in the opening sentence. All three scanned editions read वातव्याडवैश्वानरा identically. Airāvata is here demoted to a single vīthī-name (Airāvatī), not a mārga-name — a real doctrinal difference from the Purāṇas.
See also
Nāgavīthī, Gajavīthī, Airāvatī, Ārṣabhī, Govīthī, Jaradgava / Jāradgavī, Ajavīthī, Mṛgavīthī, Vaiśvānarī