I was not trying to slight Simula-67 here, which indeed comes earlier. But more readers, I think, know at least a little bit about Smalltalk than about Simula--for one thing, there are actively maintained versions of Smalltalk still out there.
Obviously, Smalltalk *syntax* is a lot different from that of C++, Perl, Python. Ruby blocks look a bit Smalltalk-ish. But the contrast I had in mind was in the semantics, where CLOS' generic functions differ from Simula/Smalltalk descendent's message passing. By pointing to a language with a notably different syntax, the point about identifying a common underlying semantics is further emphasized.