DECAPOD CRUSTACEANS OF THE WEST INDIES 129 



mostly brick to scarlet red but growths of algae furnishing upper 

 distal portion of merus and upper surface of carpus mth greenish 

 tinge. Lower mesial and lateral surfaces of palmar area of propodus, 

 proximo ventral portion of dactyl, and proximodorsal portions of im- 

 movable finger bluish cream; tubercles, tips of fingers, and all spines 

 on all podomeres cream; remainder of fingers mostly bright red with 

 small dark red areas. Second and third pereiopods mth proximal por- 

 tions of merus mostly orange red becoming more scarlet distally. 

 Fourth pereiopod lighter red on coxa and darker but bright red on 

 more distal podomeres; distal extremity of dactyl very dark red. 

 Fifth pereiopod dark red \\'ith upper surface of basis white and with 

 distal portions of distal three podomeres bearing overlay of dark 

 olive. Setae on all legs olive tan. 



Ventral surface of cephalothorax white to cream wdth lower surface 

 of carapace blue marginally ; first abdominal segment reddish tan with 

 white epimera, remainder mostly white to light cream. 



Material examined. — The Dominican collections contain 6 males 

 (carapace lengths in midline 42.0-72.0 mm) and 8 females (cl 32.5- 

 62.4 mm). The two smallest males (cl 42.9 and 43.3 mm) have the 

 abdomen sealed to the sternum, but the first pleopods are fully 

 formed. Only the largest female has the abdomen fully formed; it is 

 sub triangular in those with a carapace length of 51.2 mm or less. 



Ecological notes. — Relatively few of the streams on Dominica 

 provide a habitat suitable to support populations of the two species 

 of Callinectes. As has been pointed out above, so many of the streams 

 enter the Caribbean or Atlantic over riffles, with no estuarine habitats 

 at their mouths, that these crabs are not everywhere present and 

 appear to be rare except in a few streams such as the Mero and 

 Salisbury Rivers, both of which lack any noticeable current during 

 much of the drier seasons of the year. 



Callinectes bocourti was observed to be abundant only in the area 

 of the mouth of the Mero River. This stream is hardly more than a 

 trickle during the drier seasons, and never was it observed discharging 

 much water at its mouth. About 40 to 50 yards from its mouth, it 

 reaches sea level, broadens from 15 to 25 feet, and in some areas is 

 as much as 3 feet deep. Much of the bottom is rock strewn and else- 

 where there is sand with a shallow coat of silt. Considerable amounts 

 of garbage thrown into the area, together with the sluggish current, 

 are probably responsible for the brownish tinge of the water. The 

 outlet is usuaUy blocked by dark sand, and the water that escapes 

 from the stream bed must seep through the sand. A small tributary, 

 longer than the lagoonal area just described, but no more than 10 

 feet wide, joins the Mero within 30 feet of its mouth. It is stagnant 

 and much debris has accumulated within it. In this heavily polluted 



