योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-87, verse-71

पातालेन्द्रियरन्धेषु नागासुरकृमिव्रजैः ।
सप्तस्वर्णवकोशेषु नानाजातिजलेचरैः ॥ ७१ ॥

pātālendriyarandheṣu nāgāsurakṛmivrajaiḥ ,
saptasvarṇavakośeṣu nānājātijalecaraiḥ 71

71. pātālendriyarandhreṣu nāgāsurakṛmivrajaiḥ
saptasvarṇavakoṣeṣu nānājātijalecaraiḥ

71. nāgāsurakṛmivrajaiḥ pātālendriyarandhreṣu
ca nānājātijalecaraiḥ saptasvarṇavakoṣeṣu

71. In the sense-organ-like holes of the netherworld, it is pervaded by multitudes of Nāgas, Asuras, and worms. And in the seven golden 'va' layers, it is pervaded by various species of water-dwellers.

Words meanings summery:

• पातालेन्द्रियरन्ध्रेषु (pātālendriyarandhreṣu) - in the sense-organ-like holes of the netherworld

• नागासुरकृमिव्रजैः (nāgāsurakṛmivrajaiḥ) - by multitudes of Nāgas, Asuras, and worms

• सप्तस्वर्णवकोषेषु (saptasvarṇavakoṣeṣu) - in the seven golden 'va' layers/sheaths

• नानाजातिजलेचरैः (nānājātijalecaraiḥ) - by various species of water-dwellers

Words meanings and morphology

पातालेन्द्रियरन्ध्रेषु (pātālendriyarandhreṣu) - in the sense-organ-like holes of the netherworld

(noun)

Locative, neuter, plural of pātālendriyarandhra

pātālendriyarandhra - sense-organ-like holes of the netherworld

Compound type : Tatpuruṣa (pātāla+indriyarandhra)

• pātāla – netherworld, infernal regions
  noun (masculine)
• indriyarandhra – sense-organ hole, opening for a sense-organ
  noun (neuter)

नागासुरकृमिव्रजैः (nāgāsurakṛmivrajaiḥ) - by multitudes of Nāgas, Asuras, and worms

(noun)

Instrumental, masculine, plural of nāgāsurakṛmivraja

nāgāsurakṛmivraja - multitude/host of Nāgas, Asuras, and worms

Compound type : Dvandva-Tatpuruṣa (nāga+asura+kṛmi+vraja)

• nāga – serpent deity, cobra, elephant
  noun (masculine)
• asura – demon, anti-god, powerful being
  noun (masculine)
• kṛmi – worm, insect, grub
  noun (masculine)
• vraja – multitude, host, flock, herd
  noun (masculine)

सप्तस्वर्णवकोषेषु (saptasvarṇavakoṣeṣu) - in the seven golden 'va' layers/sheaths

(noun)

Locative, masculine, plural of saptasvarṇavakoṣa

saptasvarṇavakoṣa - seven golden 'va' layers/sheaths

Compound type : Bahuvrīhi (sapta+svarṇava+koṣa)

• sapta – seven
  numeral
• svarṇava – golden, made of gold
  adjective/noun
  Possibly related to 'svarṇa' (gold) and 'ava' (protection, favor), or simply 'svarṇa' as golden.
• koṣa – sheath, layer, cell, treasury
  noun (masculine)

नानाजातिजलेचरैः (nānājātijalecaraiḥ) - by various species of water-dwellers

(noun)

Instrumental, masculine, plural of nānājātijalecara

nānājātijalecara - water-dwellers of various species

Compound type : Tatpuruṣa (nānājāti+jalacara)

• nānājāti – various kinds/species
  noun (feminine)
• jalacara – water-dweller, aquatic animal
  noun (masculine)
  agent noun
  Formed from 'jala' (water) and root 'car' (to move), meaning 'one who moves in water'.
  Root: car (class 1)