u8 



122 



xvi LIST OF ILLUSTRATIONS 



PAGE 



F it Distribution of S. American wrens of the Troglodytes 

 musculus group. (From Chapman and Griscom, 



1924) ..■•••* 3 



13. Male genitalia of races of Ctenophthalmus agyrtes drawn 



on a map of Western Europe to show distribution of 

 races. (From Jordan, 1931) !I 5 



14. African squirrels of the genus Heliosciurus. (From 



Ingoldby, 1927) ' 



15. Respiratory siphons of larvae of Culicella morsitans and 



C.fumipennis. (From Lang, 1920) . 



16. Scapanorrhynchus owsteni. (From Norman, 193 1) . ' * 3 l 



1 7. A group of endemic Hawaiian insects . . • • 1 3 6 



18. Distribution of the species of Partula on the island of 



Moorea. (From Crampton, 1932) . . . . 138 



19. Peromyscus maniculatus. Histograms showing distribution 



of frequencies for the various values of relative tail- 

 length and relative width of the tail-stripe in eight 

 localities. (From Sumner, 1920) . . • -165 

 19A. Variation in seven characters in Peromyscus maniculatus 

 showing general failure of correlation within the race. 

 (From Sumner, 1920) x "7 



20. Specific differences between the queens of Vespa ger- 



manica F. and V. vulgaris L l 73 



a 1. Individuals of two different clones of Hydra, kept under 



similar conditions. (From Lashley, 1916) . ■ 19 1 



22. Map showing localities in which Peromyscus pohonotus 



albifrons and P. p. leucocephalus were trapped by Sumner. 

 (From Sumner, 1928) 2 37 



23. Leptodirus hohenwarti Schmidt (Silphidae) . . .271 



24. Specific characters of the Psammocharidae . . -275 



25. Gryllus. Polygons of frequency for ratio of ovipositor to 



tegmina. (From Lutz, 1908) 28 4 



26. Hypostomes of larval and adult ticks of the genus 



Argas. (From Nuttall, 191 1) 286 



27. Forelegs of some male Crabronidae . 2 95 



28. Horns of Ovis poll (male) 333 



29. Oligolectic and polytrophic bees . . • -349 



30. Internal temperatures of bees' and wasps' nests. (From 



Himmer, 1932) ..-••• 3 



