GEBIA. 97 



Gen. 33. GEBIA, Leach. 



Carapace with a triangular beak. Outer antennae with- 

 out a scale at their base. Outer jaw-feet pediform. Second 

 pair of legs with one toe ; all the legs indeed, except the 

 first, have but one toe. Abdomen long and much narrower 

 at the base than towards the middle; it is depressed and 

 ends in a large fin, of which the four side-plates are foliaceous 

 and very wide. First ring of abdomen with a pair of very 

 small filiform appendages; the four succeeding segments 

 with three pairs of false swimming-legs. 



Gebia stellata, Mont. sp. Mud-borer. (Plate VII. 

 fig. 3.) — Colour yellowish-white, covered with minute stel- 

 lated orange spots. Front of carapace roughened with 

 minute spines arranged in longitudinal rows. Length 

 nearly two inches. 



First found by Colonel Montagu at Kingsbridge, where 

 it seemed to inhabit the subterraneous passages made by 

 Solen vagina; but there is no doubt that, like some others 

 of its family, it is a great borer itself. 



Gebia deltura, Leach. — A much larger species than 

 the preceding; with the back of the abdomen membrana- 

 ceous, outer lamella of the tail slightly rounded and dilated 



H 



