17 



IX, Monograph on the Genera and Species of the 

 Malacostracous Famihj Leucosidea. 



LEUCOSIDEA. 



Testa valde indurata convexa subovata rotundata rhoni- 



boidalis aut transversissima antice subproducta. 

 Ocidi minuti tVontales. 



Antenuci' externce minutissinias in oculorum cantho inte- 

 riore insertte : 

 internee mediocies in foveolas obliquo-transversas 

 inter oculos recipiendte. 

 Pedipalpl eaierni cauleinterno sensim acuminato ; articulo 

 secundo interne palpigero : 



caule externo Hagro nullo instructo, in- 

 terne longitudinaliter excavato. 

 Pedes decern : par anticuni tequale didactylum, maris illo 

 rcEMiNiE longius ; paria alia ambulatoria, ungue sini- 

 plici instructa. 

 Abdomen in utroque sexu 7-articulatum ; articulis mediis 

 contiuentibus : 

 MAHis angustuni a segmento tertlo sensiin acu- 



niinalnni : 

 FCEMIN-E amplissinuiui medio latins ; articulo ul- 

 timo parvo penultinio abrupte angnstiore. 



This family of JMalacostraca has for its distinguishing 

 characters, a convex very hard shell ; eyes small and fron- 

 tal ; external antennai very minute, placed at the internal 

 corner of tlic eyes ', anterior pair of legs didactyle, the re.:)t 



VOL. 111. JJ 



