Carboniferous ammonoids purchased by the Zoology Department of the British Museum in 1841 from
  W. Gilbertson and presently housed in the Palaeontology Department of the Natural History Museum,
  London were the core material for the ammonoid descriptions in "Illustrations of the Geology of Yorkshire.
  Volume 2" (Phillips, 1836).  Phillips' monograph contained a geological map, sections of outcrop'
  systematic descriptions and plates of fossils from the Mountain Limestone District in Yorkshire.  Phillips'
  descriptions were much abbreviated, while his original illustrations were pencil and ink drawings.  Lack
  of information on the type species described by Phillips made their identifications in Carboniferous
  faunas for over 150 years uncertain.  Re-examination of ammonoids from the Gilbertson Collection
  revealed that the type specimens contained in the collection after being re-described and re-figured
  provide much additional information.  There are 182 specimens representing 35 species (3 holotypes, 15
  lectotypes, and 58 paralectotypes), the identity of which was confirmed as a result of this study.
  Examination of Phillips' original drawings and notes in the Library of Oxford University Museum of
  Natural History and their comparison with the material from the Gilbertson Collection revealed that
  some illustrations based on specimens from the Gilbertson Collection were omitted from the final
  publication.  These specimens are here re-described and illustrated, and their status as types is
  confirmed.