The first number corresponds to the section in Homeric Greek. The second is for the number of the exercise for that section. So §3.1 means the first exercise on section 3, while §3.2 means the second exercise on section 3.
§3.1 Exercise (Spell words using Greek letters.)
§3.1b Εxercise (diphthongs, gamma nasals) (rev. label)
§4.1 Exercise (syllables)
§4.2 Exercise (Make up your own words; spell your name)
§7.1 Exercise on Parts of Speech
§7.1 Exercise on Parts of Speech Key
§8.1 English Sentence Analysis
§8.1 English Sentence Analysis Key
§8.2 Sentence Analysis Cases Key
§8.3 Another Greek Case Exercise
§8.3 Another Greek Case Exercise Key
§9g.1 Exercise (alphabet, lexicon entries)
§9h.2 Exercise (What case would you use?)
§11.1 Sentence Analysis Chart (for Greek and English sentences in a lesson)
§13.1 Exercise (βουλή, θεά, θάλασσα)
§14.1-2 Exercise (accents)
§18.1 Exercise (verbs, present indicative, active)
§19.1 Exercise (accents in verbs)