Epiphallus

Hadrotettix and Heliastus lack pale streaks but possess trilobed epiphalli, which led me to look for other characteristics shared with the Hippiscus group.

Male genitalia strongly asymmetrical, partially concealed by sternum 9, comprised by basisclerite, paired epiphalli (left with titillator), and hypophallus; hook process (=L3 sclerite after MCKITTRICK 1964) missing (KLASS 1997).

In mature Arion the atrium is divided into upper and lower atria, with the oviduct, spermatheca duct and epiphallus opening into the upper atrium.