4IO A YEAR OF COSTA RICAN NATURAL HISTORY 



darker edging to the wing but elsewhere the yellowish color- 

 ing was confined to the front edges. These two sorts of fe- 

 males have been observed in many places where the males 

 have been found. That sort which is colored like the male 

 has been termed homoeochromatic, the other the hetero- 

 chromatic female. Of the 152 individuals from California 

 (where one male has been found), Mexico and Central Amer- 

 ica listed in the Biologia Centrali-^mericana, yy were males, 

 53 heterochromatic females and 22 homoeochromatic fe- 

 males. Erythrodiplax funerea thus exhibits a different kind 

 of sexual dimorphism from that which we have described 

 for Thaumatoneura at Juan Vinas. As funerea becomes 

 older the yellowish-brown darkens until it is blackish-brown. 

 In this mature stage there is usually a clear uncolored area 

 at the bases of the fore wings of the males and homoeochro- 

 matic females. The wing-colors of the heterochromatic fe- 

 males do not become as dark as do those of the other sort or 

 of the males, but some of them acquire a dark brown patch 

 at the bases of the hind wings. We have found funerea in 

 various localities in Guanacaste, near Turrucares, near Ala- 

 juela, and at Juan Vifias. Mr. Lankester has taken it at 

 Cachi and Professor Tristan on the Golfo Dulce and at Ori- 

 cuajo. In general the individuals taken from December to 

 March show the immature colors, while from April to August 

 they have those of the fully adult, but there are some excep- 

 tions on both sides of this rule. On the whole funerea is 

 chiefly an inhabitant of the Pacific slope of Mexico and Cen- 

 tral America, but as indicated above individuals are found 

 not rarely on the Atlantic slope as well. 



We returned along the sea beach to the town; there was 

 much driftwood in small pieces above high water mark, few 

 shells but many burrows of small sand crabs, an occasional 

 tiger beetle, probably Cicindela panamensis, with markings 

 resembling those of C. ancocisconenis. The body was eleven 



