Vaisesika Sūtra 2.1.8

विषाणी कुकुद्वान् प्रान्तेवालधिः सास्नावान् इति गोत्वे द्रुष्टं लिङ्गम् ॥८॥

viṣāṇī kukudvān prāntēvāladhiḥ sāsnāvān iti gōtvē druṣṭaṁ liṅgam ॥8॥

[viṣāṇī = poison; kukudvān = scorpion's; prāntēvāladhiḥ = one who dwells at the outskirts of a region;sāsnāvān = rabit's; iti = thus; gōtvē = cow-ness of the cow; druṣṭaṁ = visible; liṅgam = distinguishing marks;॥]

Poison of the scorpion, rabbit dwelling on the outskirts, cow-ness of the cow - are the visible distinguishing marks.