GUIDE TO CONTENTS. 



PAGE 



Introduction , 259 



Pariolius (Footnote) 2<>() 



Habits 261 



Distribution of the Pygidiidaa (Plates XXXVI-XXXIX) 269 



Chronology 270 



Location of types 271 



Sources of the material examined 274 



Zoological position of the Pygidiidae 275 



Synonymy 275 



Limits of the family Pygidiidae (Plates XL-XLI) 276 



Key to the subfamilies and genera (Text figure 1) 278 



I. Nematogenys 279 



A', inermis '. (Plate XLII, figs. 1 and 2) 280 



II. Scleronema (Plate XXXVI, text figure 2) 280 



S. operculatum (Plate XLIV, fig. 1) 281 



III. Hatcheria (Plate XXXVI, text figure 2) 281 



1. H. patagoniensis (Text figure 3) 283 



2. H. maculata (Plate XLII, figs. 3-5) 284 



3. H. titcombi (Plate XLIV, fig. 2) 284 



4. H. areolata (Text figure 4) 285 



5. H. burmeisteri (Text figure 5) 286 



6. H. macrcei (Text figure 6) 287 



IV. Pygidium 



1. P. marmoratum ■ • • -90 



2. P. palleum 291 



3. P. tigrinum 2 Jl 



4. P. tenue ( Text fi S ure 7) 292 



5. P. corduvense (Te xt % urc 8 ) 293 



• • • 9Q4- 



6. P. spegazzinn ^ v ^ 



7. P. borellii '-"" 



?8. P. eichorniarum (Plate XLIV, fig. 3 1 295 



9. P. riojanum Berg 295 



395 



