He could summon beasts of any particular type integrated with the summon, or could summon a form of the beast that was mixed with all the types of beasts integrated.
In most cases, it was better for the summon to have all the characteristics of all the different types of beasts integrated, but in some situations, such as if Adam wanted a small Canidae Beast, he could summon only a singular type of the beast.
It required a lot of mental control to decide what specific type he wanted to summon, but the process was the same thing and it required him to seep his consciousness into the beastpedia within his mind and chose what he wanted to summon.
He also realised that the special trait of the beast was dictated by the Base Beast and in the future, Adam had to be careful when deciding what beast to make the base beast of his summons as he couldn't change his mind afterwards.