NORTH AMERICAN ODONATA. 207 



mark, Norway, 70° N., for Somatochlora arctica; Norton Sound, 

 Alaska, 65° N., for Aeschna juncea ; and the Wilui River, Siberia, 

 60°-63° N., for Aeschna crenata (clepsydra), Leucorhinla ruhkunda 

 and other species. The annual isotherm of 0°C. (32° F.) passes 

 above the first of these places, but below the other two, while a por- 

 tion of the Wilui River is above the annual isotherm of — 10° C 

 ( 14° F.)- Baron de Selys mentions a wing, considered by McLachlan 

 to belong to Somatochlora metallica, collected by the Nordenskiold 

 expedition at Port Dickson, near the mouth of the Jenesei, 73° 30' 

 N., but there is no knowledge as to whence it may have been carried 

 by wind and wave. The most southern point at which dragonflies 

 have been found is Bay St. Bernard, Hoste Island, Fuegian Archi- 

 pelago, 55° 30' S. for Aeschna diffinis Ramb. (Mabille), which, in 

 point of temperature, does not compare with the northern locations 

 mentioned. 



Odonata occur in the mountainous regions of the world, but com- 

 paratively few precise records exist as to the elevations which they 

 attain. Allogaster latifrons and Cephakeschna orbifrons have been 

 taken at 10,000 ft. at Phulloth, in Bengal, Ophiogomphus severus at 

 9600 ft. in Colorado, Eplgomphus subohtusus and Cordulegasier God- 

 mani on the volcano of Irazu, Costa Rica (6000-7000 feet) and 

 Camicinia harterti on Mt. Deli, Sumatra (8000 feet). 



The number of described species of Odonata at the present writing 

 (July, 1893) is shown in the following table: 



Living througliout Fossil throughout 



Subfamilies the world the world 



genera species genera species 



Calopteryginse 33 239 3 6 



Agrioninse 88 605 7 28 



Gomphin* 46 2.54 10 28 



CordulegasterinjE 5 27 13 



Aeschniuae 23 126 2 12 



Corduliiife 22 146 12 



Libellulinse 104 525 3 26 



Total 321 1922 27 105 



The distribution of the living forms in the various zoo-geographical 

 provinces is shown on the next page in a table which has been pre- 

 pared for this paper by the writer's brother, Mr. Frederic B. Calvert ; 

 it is based on Kirby (35), but with the addition of such species as 

 have been described, and corrections made since the publication of 

 that Catalogue. 



TRAN.S. AM. ENT. SOC. XX. ADGUST. 1893. 



