SURUBRES AND OROTINA 395 



thorax were brownish-yellow, but with a metallic green re- 

 flection, and were finely punctured, the punctures not in 

 rows. The elytra were metallic green, each with ten longi- 

 tudinal rows of punctures, the under surface of body and 

 legs clay-colored. We made no observations on its relations 

 to the ants — if it have any. 



One day, while sitting quietly on a stone by the river, 

 A. saw a "nutria" (perhaps Lutra latidens), an otter-like 

 animal with gray fur and a long tail, run out of the woods 

 upon the stones a short distance upstream; then it entered 

 the water and swam across the river, seeming quite unaware 

 of her presence although she was in full view. 



It was impossible to follow the stream for any great dis- 

 tance either up or down, as the gorge had steep sides and 

 going downstream the many little tributaries increased the 

 volume of water so rapidly that the ravine bed was full. 

 At these points therefore we had either to return or scramble 

 up the side of the ravine into thick charral where we rarely 

 saw dragonflies and which was difficult walking. But the 

 little bit of wider river valley produced several valuable 

 finds. Dragonflies new to the Pacific slope of Costa Rica 

 were taken here: a new species of Philogenia, a small form 

 of Palcemnema nathalia and a little Progomphus {P. pygmcsus) 

 not previously recorded from anywhere between Guatemala 

 and Bogota. This last was hardly one and one-quarter 

 inches long with a wing-spread of one and one-half inches. 

 Its colors were dark brown and green. Its eyes, bluish- 

 green above and paler below, did not nearly meet on the 

 top of its head and the hind wings were distinctly wider 

 than the fore pair. It was swift of flight, wary, and difficult 

 to follow with the eye because its colors so nearly coincided 

 with those of the sand and reflected bottom of the river. 

 Better still, we found one transforming Progomphus and its 

 exuvia, and, on later days, the living larvae. The latter, 



