In his Post #225, Eddington7 wrote:

       I am sort of puzzled about how it came to be that the four types became 'styles' when N-S ideas were quoted or interpreted by other authors. It was generally accepted once that all the arts reflect one of two stylistic tendencies: the classical or the romantic. Since N-S choose to call two of his types with those names, perhaps others assumed (rightly or wrongly) that he was talking about styles?

    And, if not styles, what 'type of types' are they?   Classes, categories, genres, kinds? It might be, as they say, a matter of Semantics. But, in my view, semantic distinctions are all important if we are trying to understand a subject.

    Eddington: I also share you concern for semantic distinctions and I'll do my best in answering your pointed questions. First of all, apologies for leaving unanswered your Post for nearly a month; as they say in gangster's films – No discourtesy intended – .   

        I brought-in "gangster's films" with a second intention: those films are members of a category that we call a film genre and not a film style. In general, a given genre, like "gangster's films" "thrillers" or "westerns", admits a number of styles, but we may include an item in a genre even if we cannot discern in it a particular style. Without attempting here  to define genres I'd like to note that nowadays emphasis is being placed on their analysis in terms of family resemblances (Wittgenstein) and prototypicallity (E. Rosch). These two approaches, IMHO, agree quite well with, what I guess, were Norberg-Schulz original intentions in proposing his categories of landscapes.

       For those, and several other reasons that will appear later on, in answering your question of what 'type of types' are Norberg-Schulz landscape types, I'm proposing to call them landscape genres rather than landscape styles.

    As you correctly note, N-S didn't refer to them as landscape styles in his book Genius Loci . I think that the notion of landscape styles (regarding N-S types) was first introduced by J.A. Jakle in his book The Visual Elements of Landscape. Because of the wide diffusion of that book(far more than the Norberg-Schulz one) it may be that following commentators went on calling them landscape styles. In our case, because we were discussing Jakle's ideas of "Character in Landscape", (see Posts #174- #195) I thought natural to use his term "Style in Landscape" for N-S types. Now I am having second thoughts and I think that genres is more convenient a term than styles.

     I am presently building a website to be called Landscape Genres in which, among other topics, the categorization of landscapes into Genres will be further explained.