abstracts: entomology 23 



the Cocos ants are decidedly tropical whereas those of the Galapagos 

 are mainly such as belong to subtropical or temperate regions or at 

 any rate to the cooler or subalpine regions in the New World tropics. 

 * * * * The data derived from a study of the ants are too meager 

 to enable me either to accept or to reject Stewart's view that Cocos is a 

 true oceanic island of more recent origin than the Galapagos and that 

 it has received its biota as 'Flotsam and jetsam' from the Central Amer- 

 ican mainland." S. A. RohwEr. 



ENTOMOLOGY. — The ants of the Galapagos Islands. WiIvUam 

 Morton Wheeler. Proc. Calif. Acad. Sci. [4] 2: Pt. 2, 259-297. 

 June, 191 9. 



In the introduction the author gives a history of the development of 

 our knowledge of the ants of the Galapagos Islands and briefly reviews 

 the literature of the two opposing theories of the development of the 

 islands. In reference to these theories he states that "The unbiased 

 worker can only conclude from what has been written on the subject, 

 and notwithstanding the many excellent monographs that have been 

 produced on various portions of the fauna and flora, that we need a still 

 more intensive and exhaustive exploration of the islands and above all 

 a much better acquaintance with their geology than we now possess, 

 before he can definitely accept either of the hypotheses." 



The number of ants recorded from the islands comprise 36 different 

 forms representing 18 species, 10 genera and four of the five subfamilies 

 of the Formicidae. Only nine species are considered as clearly indig- 

 enous to the islands and all of these are distinctly Neotropical in their 

 affinities but all but three or four are either well-known species widely 

 distributed in tropical and subtropical portions of America or are 

 merely subspecies or varieties of such forms. The author considers 

 that no fewer than 26, or 72.2 per cent, of the 36 forms (subspecies and 

 varieties) are endemic. S. A. Rohwer. 



VOLCANOLOGY. — The composition of the gases of Kilaiiea. E. S. 

 Shepherd. Bull. Hawaiian Volcano Obs. 7: 94-97. July, 1919. 

 Since 1912, when Day and Shepherd collected the first gas samples 

 ever taken from the Kilauea crater, work has continued on the com- 

 position of these gases. Further collection was made in 19 17 and a 

 shipment of gases collected by Dr. T. A. Jaggar, Jr., director of the 

 observatory at Kilauea, has just been received. This work presents 



