448 A YEAR OF COSTA RICAN NATURAL HISTORY 



brown with small orange spots along the edges of the 

 body. 



My explorations of the vicinity of Santa Cruz began on 

 January 20, when twenty-five minutes' easy walking along 

 a dusty road to the east brought me to the Rio Medio, here 

 flowing toward the northwest; in the afternoon I went west 

 to the Rio Diria only five minutes away. Both were at this 

 time shallow, clear-water streams with a gentle fall. They 

 wound among sand and small stones, the Diria having a 

 narrower and much shadier bed than the Medio. 



On the following day I spent some time along the west 

 bank of the Diria. There were several flocks of dragonflies 

 here, chiefly both sexes of Macrothemis hemichlora, but no 

 Miathyria. Associated with one flock of hemichlora was a 

 male of Macrothemis inacuta, a somewhat larger species 

 (one and three-quarters inches long, wing-spread two and 

 one-half inches) with a pale ochre abdomen whose edges 

 bear black lines. An individual of Pantala flavescens also 

 was in one of these flocks. 



In the fringe of woods here I almost stepped on a snake 

 some four feet long, striped lengthwise with black and yel- 

 low. It was the first experience of the sort I had in Costa 

 Rica, and as I was in so many places where snakes might be 

 expected without even seeing one, some record of their un- 

 obtrusiveness may be interesting. This particular snake 

 made off rapidly and I saw it no more. 



A little over a mile west of Santa Cruz are some hills 

 known as Cerro Las Pilas. I followed a road up into them 

 and by accident found a dry brook bed apparently a favor- 

 ite place with dragonflies of the genus Gomphoides, never 

 very abundant anywhere. The Gomphoides (near G. am- 

 bigua) of both sexes were resting on the tips of twigs, usually 

 bare ones, and closely associated with another species, 

 Orthemis levis, which was more abundant. There was no 



