2 Annals Entomological Society of America [Vol. VI, 



Passing from east to west, the average annual rainfall at 

 Limon is 126.8 inches, Juan Vinas 85.6, Cartago 60.7, with 

 minimal average monthly, precipitations of 5, 2.5 and 1 inch 

 respectively (all these on the Atlantic slope), while correspond- 

 ing figures on the Pacific slope are 76 inches for Tres Rios, 76.4 

 for San Jose and 62.1 for Nuestro Amo, the minimal average 

 monthly rainfalls being .12, .43 and inches respectively. 



The abundant rainfall gives rise to many streams of all 

 sizes. Erosion and the undermining of the loose soil have cut 

 the surface of the land into many deep ravines and canyons, 

 producing a rugged topography and making travel difficult 

 and time-consuming. Within short horizontal distances are 

 great differences of elevation. This, in turn, has affected the 

 character of the vegetation and of the fauna. Pronounced 

 segregation of many living things is consequently often the 

 case, and the richness of the biota, as estimated by the number 

 of species, is greatly increased. 



Pittier, in 1908, gave the number of species of flowering 

 plants of Costa Rica as 3441 ; the corresponding number for 

 New Jersey is 1351 (Stone, 1910). Carriker, in 1910, listed 

 753 species and subspecies of birds from Costa Rica, or more 

 than half the total number (1196) for America north of Mexico 

 in the A. O. U. check list of the same year, and twice as many as 

 have been recorded in recent years for Maine (327), Colorado 

 (392) or Washington (372) ; the smallest of these three has an 

 area at least a third greater than that of Costa Rica which is 

 only 23,000 square miles. Rehn, in 1905, gave a partial list 

 of 195 species of Costa Rican Orthoptera, as against 154 species 

 in the far more thoroughly explored state of New Jersey. 

 Godman and Salvin, in 1901, enumerated 236 genera of Costa 

 Rican butterflies; Dyar, in 1902, recognized 152 genera for 

 America north of Mexico. Schaus has found 150 Costa Rican 

 species of the butterfly genus Thecla, as contrasted with 56 

 species in America north of Mexico. 



All of these characteristics make Costa Rica a Paradise to 

 the naturalist. Its variety of altitude offers variety of temper- 

 ature. The short distance from the shores of the Atlantic to 

 those of the Gulf of Nicoya, an arm of the Paciflc, and the exist- 

 ence of the transcontinental railroad render it possible to pass 

 from one to the other in ten hours; a comparison of conditions 

 at similar altitudes on the two slopes of the divide may be easily 



