ILLUSTRATIONS. 



I-III. 



IV-VIII. 



IX-XL 



XIL 



XIII-XXIII. 



XXIV-XXV. 



XXVI, 



XXVII. 



XXVIII-XXXI. 



XXXII-XXXIV. 



XXXV. 



PLATES. 



FACING PAGK. 



Galapagos Arachnida 82 



Alaska Apterygota 108 



Alaska Hymenoptera 264 



Galapagos Brachyura 292 



Alaska Mosses 348 



Alaska Anemones 408 



Map of the Galapagos Islands, showing rela- 

 tionships of Shistocerca 452 



Varieties of Shistocerca in the Galapagos 454 



Galapagos Mallophaga 492 



Eyes of Rhineura Floridana 544 



Marine Mollusca of the Galapagos 560 



TEXT FIGURES. 



2. 



10. 



II, 



PAGE. 



Discias serrifer^ man- 

 dible 289 



Discias serrifer^ outer 

 maxilliped 290 



Discias serrifer^ chela 

 of pereiopod 290 



Discias serrifer^ tail fan 291 



Edivardsia^ type 376 



jE'f/warc^^/a, arrangement 

 of mesenteries 376 



Edwardsiella^ type 377 



Ed-wardsiella sipuncu- 

 loides^ portion of body 

 wall 379 



Edwardsiella sipuncu- 

 loides, section 380 



Edwardsiella sifuncu' 

 loides, section 380 



Edwardsiella sipuncu- 

 loides^ section 381 



Edwardsiella sipuncu- 

 loides^ rudimentary 

 mesenteries 381 



13 



Edwardsiella sipuncu- 

 loides^ arrangement of 

 mesenteries 382 



Edwardsiella sipuncu- 

 loides^ section 382 



Possible relationship of 

 the species of Ed- 

 wardsia and Hexac- 

 tinise 383 



Harenactis attenuata^ 

 arrangement of mes- 

 enteries 385 



Harenactis attenuata,, 

 section 386 



18. Charisea saxicola, sec- 



tion 389 



19. Charisea saxicola^ trxQs- 



enterics 389 



20. Epiactis prolifera^ sec- 

 tion 392 



Epiactis ritteri^ section 393 

 Rhineura Jloridana^ 

 side view of head 536 



14 



15 



16. 



17 



21, 



22 



