A. Mouth of the Rosalee River (station 22), one of the larger rivers on Dominica that flows 

 over riffles almost to its mouth. Such river mouths support a decapod fauna tliat is char- 

 acteristic of riffle areas elsewhere, and the\' lack such spe;ies as Jonga serrei and Macro- 

 brachium acanthurus, which are associated with the subestuarine habitat of the mouths 

 of rivers like the Layou (B). One of the densest populations of Coenohita clypeatus observed 

 on the island occurred on the south side (right) of the mouth of this river; hundreds of 

 them were feeding there on the fruit of Terminalia catappa. (Photo courtesy C. VV. Hart, Jr.) 



B. Mouth of the Layou River (stations 14 and 15). Note the sand bar that deflects the 

 channel to the left (south). This area of the river is inhabited by Jonga j-frr^"/, juvenile 

 Xiphocaris elotigata, Macrobrachium acanthurus, M. carcinus, M. faustinuni, and Callinectes 

 sapidus, all of which seek shelter in the exposed roots of shoreline plants and in the debris 

 trapped by roots and trunks of fallen trees. Onl_\- at night do ^1/. carcinus and C. sapidus 

 move far from shore over the sandy bottom. Occupying the adjoining floodplain and banks 

 of the ri\x"r are Coenobita clypeatus, Sesarma roberti, Cardisoma guanhumi, Uca burgersi, 

 and Ucides cordatus. On the sand\' beach at the mouth of the ri\-cr, Ocypode quadrata 

 is common. (Hobbs' photo.) 



