DECAPOD CRUSTACEANS OF THE WEST INDIES 221 



pair of purple stripes extending along juncture of posterolateral 

 margins of metagastric and urogastric regions; cardiac region with 

 pair of lateral purple stripes; branchial region with two pairs of purple 

 spots, one near junction of cardiac and metagastric regions and other 

 posterolateral to cardiac region; intestinal region with pair of purple 

 spots on anterior margin lateral to midline. Lateral wall of carapace 

 white. Eyestalks pale blue basally merging with more distal purple 

 band; distal portion white below, cream above, with reddish-brown 

 irregular longitudinal stripe filling projection into black fasceted area. 

 Third maxillipeds white. 



Chelipeds with white basal segments; ischium increasingly pinkish 

 purple distally; merus and carpus pinkish purple, latter royal purple 

 above, former \vith royal purple tubercles and similarly colored 

 distal band; chela royal purple in upper dactylar quarter fading 

 through blue to white; both fingers white except for upper proximal 

 purple area on dactyl. Articular membranes distal to end of merus 

 partially scarlet. 



Second through fifth pereiopods with coxa and basis white, ischium 

 lavender and distal podomeres mostly purple above and white below; 

 light area along posterior surfaces of merus on third and fourth legs; 

 fringes of long gray setae on aU four periopods, especially conspicuous 

 on second. Sternum and abdomen white; latter with few pale blue 

 markings. 



Smaller individuals possess a more intricately pencilled blue area 

 on the dorsal surface of the carapace; the shade of blue is highly 

 variable, and sometimes almost green. 



Material examined. — The Dominican collections contain 23 males 

 (carapace lengths 16.2-56.6 mm), 13 females (cl 10.4-45.8 mm), and 

 3 juveniles (cl 4.8-6.3 mm). The abdomen is very narrow in the 

 smallest female but is fully developed at a carapace length of about 

 25 mm. 



Ecological notes. — Almost certainly, this crab is far more abun- 

 dant on Dominica than our two locality records indicate. It was first 

 encountered in a low, poorly drained area near the mouth of the 

 Layou River, among coconut trees and bananas, the same area 

 in which Cardisoma guanhumi is also abundant. In the large mudflat 

 just south of Portsmouth (pi. 4a), it occurs in much larger numbers. 



In the Portsmouth locality, it burrows from along the shore, a few 

 feet above the water table, out to at least 100 feet into the flat, 

 probably entirely across it and around its entire margin. Here the 

 burrows are interspersed between those of Uca and Goniopsis, and 

 just below those of adult Cardisoma, which are abundant on the land 

 side of the buttress roots of Pterocarpus. In a 100- square-foot area, 

 eight of these crabs were seen at the mouths or within a few feet of 



