146 S. I. Smith on American Crustacea. 



Family, Bosciad.e. 

 Pseildothelphusa Saussure. 



Potamia Latreille, Cours d'eutomologie, p. 338, 1831 {teste Edwards); Edwards et 

 Lucas, Voyage de d'Orbigny dans I'Amerique meridionale, Crust., p. 22, 1843; 

 White, List of the Crustacea iu the British Museum, p. 30, 1847 ; Dana, United 

 States Exploring Expedition, Crust, p. 293 ; Saussure, Crustaces noveaux des An- 

 tilles et du Mexique, p. 19, 1858 {iion Robineau-Desvoidy). 



Boscia Edwards, Histoire natureUe des Crust , tome ii, p. 14, 1837 ; Annales des Sci- 

 ences naturelles, 3™® serie, Zoologie, tome xx, 1853, p. 207 ; A. Edwards, Annales 

 de la Societe entomologique de France, 4™e serie, tome vi, 1866, p. 203. 



Pseudothelphusa Saussure, Revue et Magasin de Zoologie, 1857, p. 305 {teste Saus- 

 sure). 



Latreille's name, Potamia, given in 1831, was properly rejected by 

 Edwards on account of its previous use, in 1830, by Robineau-Des- 

 voidy, for a genus of Diptera, but the name Hoscia, proposed by 

 Edwards in 1837, is quite as objectionable, having been used, accord- 

 ing to Agassiz's Nomenclator Zoologicus, by Leach, in 1813, for a 

 genus of Cimpedia, by Schweigger, in 1820, for a genus of Polyps, 

 and by Leach again, in 1824, for a genus of Coleoptera. Pseudothel- 

 phusa, although at first proposed as a new genus, does not dilFer es- 

 sentially from the species of Edwards' JBoscia which have no superior 

 frontal crest, and was finally united with Potamia by Saussure him- 

 self, so that it may properly be adopted for the genus as defined by 

 Edwards. 



Pseudothelphusa, as here limited, includes the following American 

 species : — 



P. Americana Saussure, from Hayti. 



P. gracilipes {Poscia gracilipes A. Edwards, Annales de la Societe 

 entomologique de France, 4""^ serie, tome vi, 1866, p. 204), from Haute 

 Vera-Paz, Gautemala. 



P. plana, sp. no v., from Peru. 



P. rnacropa {Boscia macropa Edwards, Archives du Museum 

 d'Histoire naturelle, Paris, tome vii, p. 175, pi. 12, fig. 3), from Bo- 

 livia. 



P. Chilensis {Potamia Ghilensis Edwards et Lucas, Voyage de 

 d'Orbigny dans I'Amerique meridionale. Crust,, p. 22, pi. 10, fig. 1), 

 from Lima, Peru. 



P. denticulata {Boscia denticulata Edwards, Annales des Sciences 

 naturelle, Zoologie, 3"'*^ serie, tome xx, 1853, p. 208), from Guiana. 



P. Bocourti, {Boscia Bocourti A. Edwards, loc. cit., p. 203), from 

 the River Coban, Haute Vera-Paz, Gautemala. 



