IXTRODUCTIOX 



and I have most gratefully to acknowledge the skill and patience with which they 

 have seconded our efforts to give accurate reproductions of the specimens figured. 



All the figures given upon the plates are of the natural size. The figures in 

 the text, which are inserted for the purpose of illustrating structural details, 

 were originally drawn upon a scale of ten times linear, and afterwards reduced 

 to a uniform scale of five times the natural size, the same scale being retained 

 throughout for the purpose of easy comparison. 



Now that the subject is in a state to admit of the satisfactory production of a 

 ^lonograph of the British Graptolites, being myself too busy with other matters 

 to do the necessary detailed labour, I have, with the consent of the Council of_the 

 Palaeontographical Society, handed over the work of the preparation and illustra- 



Parkes-Lapworth Microscope.' 



tion of the Monograph to the two English palgeontologists best qualified for the 

 task — Miss Gr. L. EUes, of Newnham College and the Woodwardian Museum, 

 Caml)ridge, and Miss E. M. R. Wood, of NeAvnham College and the Birmingham 

 University. The present part is the first instalment of their labour. For all 

 matters connected with the description and illustration of the various species, etc., 

 they alone must be credited ; for the general plan and the editing of the Avork 

 throughout I am responsible. 



On their behalf as well as my own I must here gratefully acknowledge how 

 freely all type specimens of Graptolites already described have been placed at our 

 service, and how all those who have collections of Graptolites, either public or 

 private, have permitted us to stud}' such specimens as Ave considered necessary 

 for the purpose of this Avork. In connection with this first part we may mention, 

 among others, the Woodwardian IMuseum, Cambridge ; tlie British Museum of 

 Natural History, South Kensington ; the Geological Survey Musemns of London, 

 1 J. Parkes and Sou, Vesey Street, Birmingham. 



