Ten major natural history museum libraries, botanical libraries, and research institutions have joined to form the Biodiversity Heritage Library Project. The group is developing a strategy and operational plan to digitize the published literature of biodiversity held in their respective collections. This literature will be available through a global “biodiversity commons.” The participating libraries have over two million volumes of biodiversity literature collected over 200 years to support the work of scientists, researchers, and students in their home institutions and throughout the world. The 10 member libraries of the Biodiversity Heritage Library (BHL) members now have over 1.124 million pages of key taxonomic literature available on the web. http://www.biodiversitylibrary.org/
Among other digitised books on this site is Schoenherr's Genera et species Curculionidum, cum synonymia hujus familae species novæ / a C.J. Schoenherr; species novae aut hactenus minus cognitae, descriptionibus a L. Gyllenhal, C. H. Boheman entomologis aliis illustratæ. You can go straight to it by clicking here.
AnimalBase is a service provided by the University of Göttingen, Germany. Its objective is to provide free access for all scientists to the old zoological literature, particularly to those important publications where name-bearing zoological taxa were originally described. The literature is digitized in image format by the SUB Göttingen (the university library). In the first 2-year period (2003-2005) they digitized nearly all taxonomically relevant zoological literature up to 1770 (about 400 works). http://www.animalbase.de/ Not all texts are currently still available, but some at least can be found on Gallica (see below)
This digital edition of the important and out-of-print Biologia Centrali-Americana makes all 58 biological volumes available. Descriptions of over 50,000 and images of over 18,00 species of animals and plants are now accessible - the electronic Biologia Centrali-Americana. http://www.sil.si.edu/DigitalCollections/bca/
Useful search tool for academic literature. Google Book Search.