LIST OF ILLUSTRATIONS XV 



Page 



2. Contrasting dorsal views of tiireo fruntal processes on lieads of koI- 



dlers of three American spinitermes ; note that the processes are 

 slightly asymmetrical. «. Soldier of Miroiermes {Spinitermea) 

 ro'bustufi Snyder. (Ixiamas, I'olivia, December, 1921.) 1). Soldier of 

 Mirotcnncfi (Spimtcj-mcs) hrevicornutus Holmgren. Rosario, Bo- 

 livia, Noveml)er, 1921.) c. Soldier of Mirotcrmea {iipinitcmics) 

 trispinous Hagen. (Cachuela Esperanza, Beni River, Bolivia, 

 March, 1922.) (Figs, ^a, h, and c Camera Liicida, all dravra to 

 the same scale) C2 



3. Contrasting views of soldiei*s of new Neocaprltermes. a. Dorsal view 



of head and pronotum of the soldier of C'apritermcs {Neocapri- 

 tenncfi) liofiJaiiai Snyder showing twisted mandibles. &. Lateral 

 view of head and pronotum of the soldier of Cap>-itcnnes (Neocap- 

 ritermes) liopkinai Snyder showing twisted mandibles, c Dorsal 

 view of head and pronotum of the soldier of Capritermes (Neo- 

 cnpritermes) braziliensis Snyder; note narrow head and twisted 

 mandibles 05 



Tub MiNrai-\LS of Obsiuiax Cliff, Yellowstoni-: Natio.nal Park, ani> 



THEIR OiaOTN 



By William F. Foshag 



1. Two habits of feldi^par from ihe lithophy.sae of Obsidian Cliff 8 



2. Section of ring in lithophysae showing the relation of the tridymite 



(white) to the feldspar (stippled) 9 



3. Crystal habit of f;iyalite from the lithophysae of Obsidian Cliff 10 



4. Crystal habit of fayalite from the lithophysae of Obsidian Cliff—. 11 



5. Diagram .showing relative solubility of the forms of silica 15 



A UKVISION OF THE AmKKKAN LICK OF THE GENUS I'EIUCULUS, TOGETHER 

 WITH A CONSIDEKATION OF THE SIGNIFICANCE OF TIIKIR OFX)aRAPIIICAL AND 

 HOST ni.STRlHTITION 



By H. E. Ewing 



1. Tlio riglit antenna of female from above of; A, Pedwulus humanity 



htimanu.^ Linnaeus; B, Pcdiculus human us aw? er/c'0«/««, new variety ; 



and C. Pcdiculus humanus nlgritarum Fabricius 4 



2. Drawings of the right thoracic spiracle of a fera.nle louse of five dif- 



ferent kinds of Pediculi 5 



?,. Lateral views of the right pleural plates of females of A, Pcdiculus 

 hunianns Inniuiiius Linnaeus, from Germany; B, P. humanus ameri- 

 ca/nus, new variety, from Indian mummy ; C. P. humanus nigri- 

 iarum Fabricius, from negro in Africa : D, P. consohrinus Piaget. 

 from bi'owii-hipped marmoset G 



4. A. lateral view of first pleural plate of right side of Pcdiculus (Para- 



pediculus) atclophilus, new species; B, lateral view of right pleural 

 plates of female of /'C(Z/CM?«A (Parapediculus) c/iapm/, new spe<ues_ 11 



5. Anterior view of distal end of left hind tibia of males of three species 



of Pediculu^, all drawn to the same scale 13 



0. Ventral view of end of left anterior leg of male of Pcdiculus (Pedl- 



culux) humanus nlgritarum Fabricius 16 



7. Ventral, or posterior, view of end of left anterior leg of male of 



Pcdiculus ( Pediculus) humanus Linnaeus, taken in Germany 24 



