202 A YEAR OF COSTA RICAN NATURAL HISTORY 



in spite of its smallness the insect was conspicuous. Its 

 jumping powers were very great, but we never saw it fly. 

 We observed it in August, late September, early October, 

 early December, February, March and late April, on which 

 last occasion it seemed scarcer. On December 2 it was also 

 found in (to us) new surroundings — in little cavities, slightly 

 larger than the crickets themselves, in earth occupied by a 

 nest of small black ants. The crickets were sometimes in 

 holes below the surface of the earth so as to be only partially 

 visible. The ants apparently did not regard them with any 

 hostility. 



Another, larger, species of Rhipipteryx, R. limbata (ii mm. 

 long) found on rocks below the waterfalls on August 3, but 

 less abundantly, had the legs black with a whitish line on 

 each, the rest of the body colored similarly to biolleyi. On 

 February 14 two of them were seen flying, a mode of loco- 

 motion new for them in our experience. After that I tried 

 to make biolleyi fly, but it always jumped, although it has 

 well-developed wings. The legs of Rhipipteryx are curiously 

 modified, the tibiae of the first legs being deeply grooved 

 lengthwise, presumably permitting the tarsus to be folded 

 back into the groove, and the tibia of the third leg gives the 

 appearance of possessing three terminal and two anteter- 

 minal claws. 



On the rocks below the falls and also in the dripping 

 vegetation on the rock faces at the side of the waterfall 

 were some somber-hued grouse-locusts or Tettigids {Allo- 

 tettix peruvianus), whose leaping powers were not as great 

 as those of Rhipipteryx; they were 10.5 mm. long, and were 

 noted in August and in February. 



On September 29 several brown pink-winged walking 

 sticks {Pseudophasma menius) flew up under our feet, and 

 we took an oddly colored small grasshopper {Dellia minia- 

 tula) 15 mm. or Vs inches long, which had much metallic 



