The biblioblogosphere is comprised of the institutional publication of blogs of libraries and the personal, professionally-oriented publication of blogs by librarians. Since introduction of this neologism in 2004, a number of researchers have examined this particular class of bloggers and blogging. However, there is limited investigation into the structure and connectivity of blogs within the biblioblogosphere. This article reports a study of interlinkage patterns within a sample of 1,604 biblioblogs. Findings suggest the biblioblogosphere conforms to the locally dense, globally sparse structure of blog networks established by previous studies of other blog types. The majority of blogs within the sample did not link to any other sampled blog. Those that did tended to cluster according to library type, blog subject, or geographical proximity. About one-third of the interlinked blogs were located within a single, massive component (that is, a networked group of blogs), while the rest were in smaller networks of two or three nodes. Personal biblioblogs, characterized as blogs published by individuals independently of an institution, are more likely to be located within a more densely populated network than institutional blogs. These findings indicate that "personal-professional" bibliobloggers are actively shaping the structure of the library blogosphere, while institutional blogs demonstrate much less overall connectivity. (Contains 5 tables and 1 figure.)