On the upper chin of the sisumara is Agasti; on its lower chin, Yamaraja; on its mouth, Mars; on its genitals, Saturn; on the back of its neck, Jupiter; on its chest, the sun; and within the core of its heart, Narayana

Expressions researched:
"On the upper chin of the sisumara is Agasti; on its lower chin, Yamaraja; on its mouth, Mars; on its genitals, Saturn; on the back of its neck, Jupiter; on its chest, the sun; and within the core of its heart, Narayana"

SB Canto 5

On the upper chin of the śiśumāra is Agasti; on its lower chin, Yamarāja; on its mouth, Mars; on its genitals, Saturn; on the back of its neck, Jupiter; on its chest, the sun; and within the core of its heart, Nārāyaṇa. Within its mind is the moon; on its navel, Venus; and on its breasts, the Aśvinī-kumāras. Within its life air, which is known as prāṇāpāna, is Mercury, on its neck is Rāhu, all over its body are comets, and in its pores are the numerous stars.

SB 5.23.7, Translation:

On the upper chin of the śiśumāra is Agasti; on its lower chin, Yamarāja; on its mouth, Mars; on its genitals, Saturn; on the back of its neck, Jupiter; on its chest, the sun; and within the core of its heart, Nārāyaṇa. Within its mind is the moon; on its navel, Venus; and on its breasts, the Aśvinī-kumāras. Within its life air, which is known as prāṇāpāna, is Mercury, on its neck is Rāhu, all over its body are comets, and in its pores are the numerous stars.