ii PREFACE. 



supply of fine specimens from his rich collection of Chalk Echinoderms, in order 

 to furnish the artist with the best possible specimens for the plates, has been of 

 very great assistance in carrying out the work, and for which he now expresses 

 his deep obligations, and records his lasting gratitude for all his most kind, 

 generous, and friendly aid from first to last. 



4, St. Maegaket's Teeeace, Cheltenham : 

 2bth April, 1882. 



N 



