DECAPOD CRUSTACEANS OF THE WEST INDIES 145 



basis and ischium only slightly darker; merus yellow above, brown 

 below but distal portion entirely yellow. Carpus yellow except dorsally 

 where brown but with yellow dorsomesial and distal margins; 

 propodus with upper proximomesial and proximolateral surfaces 

 brown, remainder of palm yellow; both fingers yellow proximally and 

 white distally with white tubercles on opposable surfaces. (In some 

 individuals, distal four podomeres yellow and wliite with only lower 

 surface of merus and lower proximomesial surface of carpus brown.) 

 Remaining pereiopods with coxae yellowish tan, basis and ischium 

 slightly darker; merus brown except for distal yellowish-green band; 

 distal podomeres mostly brown with greenish-yellow areas adjacent 

 to articulations. 



Sternum pale yellowish tan with pale yellow lines marking sternal 

 sutures. Abdomen brown at base fading to tan toward telson. 



Material examined. — The Dominican collections contain 50 

 males (carapace lengths in midline 7.2-55.8 mm), 57 females (cl 7.2- 

 58.8 mm), including 3 with eggs (cl 44.1-55.5 mm) and 7 with young 

 (cl 48.3-58.8 mm), and 102 juveniles (cl 3.6-8.2 mm). As indicated 

 below, the first rudiments of pleopods may appear in both males and 

 females at a carapace length of 7.2 mm, but other specimens as much 

 as a millimeter longer show no sign of abdominal appendages. 



Ecological notes. — Except for its apparent absence in the lower- 

 most portions of those streams with flooded mouths, Guinotia dentata 

 frequents most parts of the island where fresh water is readily accessible 

 in streams, ditches, ponds, lakes, seepage areas, or burrows. In fact, 

 this crab was the first crustacean observed on Dominica by Hobbs. 

 On his trip from the airport to Clarke Hall in November 1963, he 

 saw a large male of tliis species crossing the road at about 9:00 a.m. 

 just south of the bridge at Deux Branches, a tributary to the Pagua 

 River on the windward side of the island. 



In the Layou River drainage, it occurs from just above the lower- 

 most bridge well onto the slopes of Morne Trois Pitons, and one 

 individual was seen in Boeri Lake at an altitude of 2,850 feet. It is 

 a denizen of seepage areas, where it constructs burrows. In streams, 

 it is by no means confined to pools; however, almost every pool more 

 than a few feet in diameter is frequented by one of these crabs. 

 Often it digs shallow excavations under large stones that are sur- 

 rounded by water, and many stones embedded in the bank of a 

 stream have crab excavations beneath them that extend for a foot 

 or more into the bank. While burrows are common in seepage areas, 

 this crab has been found neither in low-lying areas with Cardisoma 

 nor in the drier areas with the two species of Gecarcinus. 



On the morning of February 19, 1966, Hobbs was observing a 

 large pool on Mannet's Gutter. Using a line baited with an earth- 



