PEEFACE. 



Having completed the descriptions of the Fossil Echinoidea from the two lower horizons 

 of the Tertiaries of Western Sind, we began to study the forms which were found in 

 the Khirthar and Nari series of that country. In all this research we obtained but 

 little assistance from the many admirable works which have of late years been written 

 on the Tertiary Echinoidea. We found that we were working amongst faunas which 

 were singularly isolated. Moreover, not a little perplexity was caused by our inability 

 to discover traces of many of the species which were described by d'Archiac and 

 Haime in their classical work, 'Sur les Animanx Fossiles de I'lnde,' as characterizing 

 Nummulitic strata. 



Some very valuable descriptions of Egyptian and Lybian Nummulitic Echinoidea 

 have lately been published bydeLoriol; and we considered that it might be advisable 

 to investigate the fine collection of Echinoidea from the Tertiaries of Kachh and 

 Kattywar which had been carefully collected by the Geological Surveyors of India 

 under the care of H. B. Medlicott, Esq., F.R.S,, the Superintendent of the Survey. 

 We hoped to trace affinities between the Sindian and Kachh faunas on the one hand, 

 and between those of Egypt and Kachh and Kattywar on the other. Hence this work 

 appears before our Memoirs on the Fossil Echinoidea of Western Sind are completed. 



